diff --git a/img/do_while.svg b/img/do_while.svg
new file mode 100644
index 0000000..2820310
--- /dev/null
+++ b/img/do_while.svg
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="163px" height="340px" viewBox="-0.5 -0.5 163 340" content="&lt;mxfile host=&quot;app.diagrams.net&quot; modified=&quot;2020-03-25T09:17:22.437Z&quot; agent=&quot;Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36&quot; etag=&quot;V_k_Mq8pM63YYHRX4fR-&quot; version=&quot;12.9.2&quot; type=&quot;google&quot;&gt;&lt;diagram id=&quot;ALJ9cRBg6StV6unFPeWv&quot; name=&quot;Page-1&quot;&gt;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&lt;/diagram&gt;&lt;/mxfile&gt;" style="background-color: rgb(255, 255, 255);"><defs/><g><path d="M 51.03 61 L 51.03 81 L 51.03 71 L 51.03 80.76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 51.03 88.76 L 47.03 80.76 L 55.03 80.76 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><rect x="1" y="1" width="100" height="60" rx="7" ry="7" fill="#ffffff" stroke="#000000" stroke-width="2" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 31px; margin-left: 2px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><font style="font-size: 14px"><b>int i = 0</b></font></div></div></div></foreignObject><text x="51" y="35" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">int i = 0</text></switch></g><path d="M 51.03 151 L 51.03 171 L 51.03 161 L 51.03 170.76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 51.03 178.76 L 47.03 170.76 L 55.03 170.76 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><rect x="1" y="91" width="100" height="60" rx="7" ry="7" fill="#ffffff" stroke="#000000" stroke-width="2" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 121px; margin-left: 2px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><font style="font-size: 14px"><b>"%d%n", i</b></font></div></div></div></foreignObject><text x="51" y="125" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">"%d%n", i</text></switch></g><path d="M 101 231 L 131.03 231 L 131.03 71 L 61.24 71" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 53.24 71 L 61.24 67 L 61.24 75 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 151px; margin-left: 151px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; "><b>true</b></div></div></div></foreignObject><text x="151" y="155" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">true</text></switch></g><path d="M 51 281 L 51 320.76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 51 328.76 L 47 320.76 L 55 320.76 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 299px; margin-left: 71px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; "><b>false</b></div></div></div></foreignObject><text x="71" y="303" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">false</text></switch></g><path d="M 51 181 L 101 231 L 51 281 L 1 231 Z" fill="#ffffff" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 231px; margin-left: 2px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><font style="font-size: 14px"><b>i &lt; 10</b></font></div></div></div></foreignObject><text x="51" y="235" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">i &lt; 10</text></switch></g></g><switch><g requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"/><a transform="translate(0,-5)" xlink:href="https://desk.draw.io/support/solutions/articles/16000042487" target="_blank"><text text-anchor="middle" font-size="10px" x="50%" y="100%">Viewer does not support full SVG 1.1</text></a></switch></svg>
\ No newline at end of file
diff --git a/img/for.svg b/img/for.svg
new file mode 100644
index 0000000..6b1dd74
--- /dev/null
+++ b/img/for.svg
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="340px" height="295px" viewBox="-0.5 -0.5 340 295" content="&lt;mxfile host=&quot;app.diagrams.net&quot; modified=&quot;2020-03-25T09:13:36.837Z&quot; agent=&quot;Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36&quot; etag=&quot;skXCgtUu2ggFO8zTyuH4&quot; version=&quot;12.9.2&quot; type=&quot;google&quot;&gt;&lt;diagram id=&quot;asvwDEWpePHf3AiSwIBx&quot; name=&quot;Page-1&quot;&gt;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&lt;/diagram&gt;&lt;/mxfile&gt;" style="background-color: rgb(255, 255, 255);"><defs/><g><path d="M 101 156 L 170.76 156" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 178.76 156 L 170.76 160 L 170.76 152 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 146px; margin-left: 141px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; "><font style="font-size: 14px">true</font></div></div></div></foreignObject><text x="141" y="150" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">true</text></switch></g><path d="M 51 206 L 51 275.76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 51 283.76 L 47 275.76 L 55 275.76 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 1px; height: 1px; padding-top: 237px; margin-left: 31px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; background-color: #ffffff; white-space: nowrap; ">false</div></div></div></foreignObject><text x="31" y="241" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">false</text></switch></g><path d="M 51 106 L 101 156 L 51 206 L 1 156 Z" fill="#ffffff" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 156px; margin-left: 2px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><font style="font-size: 14px">i &lt; 10</font></div></div></div></foreignObject><text x="51" y="160" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">i &lt; 10</text></switch></g><path d="M 51 51 L 51 95.76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 51 103.76 L 47 95.76 L 55 95.76 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><rect x="1" y="1" width="100" height="50" rx="7" ry="7" fill="#ffffff" stroke="#000000" stroke-width="2" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 26px; margin-left: 2px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><font style="font-size: 14px">int i = 0</font></div></div></div></foreignObject><text x="51" y="30" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">int i = 0</text></switch></g><path d="M 231 181 L 231 215.76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 231 223.76 L 227 215.76 L 235 215.76 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><rect x="181" y="131" width="100" height="50" rx="7" ry="7" fill="#ffffff" stroke="#000000" stroke-width="2" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 156px; margin-left: 182px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><font style="font-size: 14px">"%d%n", i</font></div></div></div></foreignObject><text x="231" y="160" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">"%d%n", i</text></switch></g><path d="M 281 251 L 331 251 L 331 76 L 61.24 76" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 53.24 76 L 61.24 72 L 61.24 80 Z" fill="none" stroke="#000000" stroke-width="2" stroke-miterlimit="10" pointer-events="all"/><rect x="181" y="226" width="100" height="50" rx="7" ry="7" fill="#ffffff" stroke="#000000" stroke-width="2" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 251px; margin-left: 182px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><font style="font-size: 14px">i++</font></div></div></div></foreignObject><text x="231" y="255" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">i++</text></switch></g></g><switch><g requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"/><a transform="translate(0,-5)" xlink:href="https://desk.draw.io/support/solutions/articles/16000042487" target="_blank"><text text-anchor="middle" font-size="10px" x="50%" y="100%">Viewer does not support full SVG 1.1</text></a></switch></svg>
\ No newline at end of file