graph G {
    compound="true"
    rankdir="TB"
    bgcolor="white"
    fontname="Tahoma"

    node [
        fixedsize="false"
        fontname="Tahoma"
        color="white"
        fillcolor="deepskyblue2"
        fontcolor="black"
        shape="box"
        style="filled"
        penwidth="1.0"
    ]
    edge [
        fontname="Arial"
        color="#00688b"
        fontcolor="black"
        fontsize="12"
        arrowsize="0.5"
        penwidth="1.0"
    ]




    "cpp" -- "cpp" [label=" 19 ", penwidth="10", color="#a0a0a0FF"];
    "java" -- "java" [label=" 12 ", penwidth="6", color="#a0a0a0B7"];
    "python" -- "python" [label=" 5 ", penwidth="2", color="#a0a0a070"];
    "cpp" -- "python" [label=" 4 ", penwidth="2", color="#00688b70"];

}