/*
 * Date: 07/07/2015
 * Created by: Ton Chanh Le (chanhle@comp.nus.edu.sg)
 * Adapted from "Inductive Invariants for Nested Recursion"
 * by Sava Krstic and John Matthews
 */

extern int __VERIFIER_nondet_int();

int g(int x)
{
  if (x == 0) 
    return 0;
  else
    return g(g(x - 1));
}

int main() {
  int x = __VERIFIER_nondet_int();
  g(x);
}