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="#DC143C"
        fontcolor="black"
        fontsize="12"
        arrowsize="0.5"
        penwidth="1.0"
    ]




    "a3-mega" -- "a3" [label=" 5291 ", penwidth="10", color="#DC143CFF"];
    "a2" -- "a3" [label=" 2624 ", penwidth="4", color="#DC143C93"];
    "a2" -- "a3-mega" [label=" 2452 ", penwidth="4", color="#DC143C93"];

}