extern int __VERIFIER_nondet_int();
void abort() { };
                                                                                                                                                          
                                                                             

int id(int x);
int id2(int x);

/*@ 
    requires (1);
    ensures (((((((x == 0) || (x == 4)) || ((5 == \result) && (5 == x))) || ((((3 == \result) && (x <= 4)) || (x == 2)) && (2 <= x))) || (((\result == 1) && (x <= 2)) && (1 <= x))) || (5 < x)));
@*/
int id(int x) {
  if (x==0) return 0;
  return id2(x-1) + 1;
}

/*@ 
    requires (1);
    ensures (((((((x == 0) && (\result == 0)) || (x == 1)) || (((\result == 2) && (x <= 3)) && (2 <= x))) || (4 < x)) || (((3 == x) || (\result == 4)) && (3 <= x))));
@*/
int id2(int x) {
  if (x==0) return 0;
  return id(x-1) + 1;
}

int main() {
  int input = 5;
  int result = id(input);
  if (result != 5) {
    ERROR: {/*@ assert(0); */;abort();}
  }
}