digraph CFG {
  node [fontname="Helvetica"];
  n534 [label="START", shape=ellipse, style=filled, color=gray];
  n534 -> n540;
  n540 [label="5", shape=box];
  n540 -> n541;
  n541 [label="CALL n", shape=box, style=filled, color=orange];
  n541 -> n536;
  n541 -> n543;
  n536 [label="START n(a)", shape=ellipse, style=filled, color=green];
  n536 -> n539;
  n539 [label="a", shape=box];
  n539 -> n537;
  n537 [label="END n(a)", shape=ellipse, style=filled, color=green];
  n537 -> n543;
  n537 -> n554;
  n543 [label="RET n", shape=box, style=filled, color=orange];
  n543 -> n551;
  n551 [label="5", shape=box];
  n551 -> n552;
  n552 [label="CALL n", shape=box, style=filled, color=orange];
  n552 -> n536;
  n552 -> n554;
  n554 [label="RET n", shape=box, style=filled, color=orange];
  n554 -> n555;
  n555 [label="5", shape=box];
  n555 -> n556;
  n556 [label="CALL m", shape=box, style=filled, color=orange];
  n556 -> n545;
  n556 -> n558;
  n545 [label="START m(a)", shape=ellipse, style=filled, color=green];
  n545 -> n548;
  n548 [label="a", shape=box];
  n548 -> n549;
  n549 [label="1", shape=box];
  n549 -> n550;
  n550 [label="a + 1", shape=box];
  n550 -> n546;
  n546 [label="END m(a)", shape=ellipse, style=filled, color=green];
  n546 -> n558;
  n558 [label="RET m", shape=box, style=filled, color=orange];
  n558 -> n559;
  n559 [label="n(5) + m(5)", shape=box];
  n559 -> n535;
  n535 [label="END", shape=ellipse, style=filled, color=gray];
}