digraph M1 {
0 [label="0,?,?,?"]
1 [label="1,?,?,?"]
2 [label="2,?,9,?"]
3 [label="3,?,9,3"]
4 [label="4,3,9,3"]
5 [label="5,4,9,3"]
6 [label="stop"]

0 -> 1 [label="    int x,y;"]
1 -> 2 [label="    x = 9;"]
2 -> 3 [label="    y = 3;"]
3 -> 4 [label="    h = 3;"]
4 -> 5 [label="    h = a + y;"]
5 -> 6 [label="    ret"]
}