// verifast_options{disable_overflow_check target:ILP32}
extern void abort(void);
//@ requires true;
//@ ensures true;


void reach_error()
//@ requires false;
//@ ensures true;
{}void assume_abort_if_not(int cond) 
//@ requires true;
//@ ensures true;
{  if(!cond) {abort();}
}
void __VERIFIER_assert(int cond) 
//@ requires (1 <= cond);
//@ ensures (1 <= cond);
{  if (!(cond)) {
      ERROR: {reach_error();abort();}
  }
  return;
}
int __VERIFIER_nondet_int();
//@ requires true;
//@ ensures true;
int main() 
//@ requires module(cggmp2005_variant__verifast_instrumented, true);
//@ ensures junk();
{
    //@ open_module(); 
    int lo, mid, hi;
    lo = 0;
    mid = __VERIFIER_nondet_int();
    if (!(mid > 0 && mid <= 1000000)) return 0;
    hi = 2*mid;
while (mid > 0)
//@ invariant (((lo + (mid * 2)) == hi) && (lo <= hi));
    {
        lo = lo + 1;
        hi = hi - 1;
        mid = mid - 1;
    }
    __VERIFIER_assert(lo == hi);
    return 0;
}