void abort() { };
                                            
  
                                                             
  
                                      

                        
                                                                                                                                                          
                                                                     
extern unsigned int __VERIFIER_nondet_uint();
/*@ 
    requires ((\old(cond) != 0)) && (cond != 0);
    ensures ((\old(cond) != 0)) && (1);
@*/
void __VERIFIER_assert(int cond) {
  if (!(cond)) {
    ERROR: {/*@ assert(0); */;abort();}
  }
  return;
}
int main() {
  unsigned int w = __VERIFIER_nondet_uint();
  unsigned int x = w;
  unsigned int y = __VERIFIER_nondet_uint();
  unsigned int z = y;
/*@
loop invariant (((z == y) && (x == w)));
@*/
  while (__VERIFIER_nondet_uint()) {
    if (__VERIFIER_nondet_uint()) {
      ++w; ++x;
    } else {
      --y; --z;
    }
  }
  __VERIFIER_assert(w == x && y == z);
  return 0;
}