/*
 * Benchmarks used in the paper "Commutativity of Reducers" 
 * which was published at TACAS 2015 and 
 * written by Yu-Fang Chen, Chih-Duo Hong, Nishant Sinha, and Bow-Yaw Wang.
 * http://link.springer.com/chapter/10.1007%2F978-3-662-46681-0_9
 * 
 * We checks if a function is "deterministic" w.r.t. all possible permutations 
 * of an input array.  Such property is desirable for reducers in the 
 * map-reduce programming model.  It ensures that the program always computes 
 * the same results on the same input data set.
 */

#define fun sep

extern void abort(void);
#include <assert.h>
void reach_error() { assert(0); }
extern int __VERIFIER_nondet_int(void);

int N;

int sep (int x[N])
{
  long long ret =0;
  for(int i=0;i<N;i++)
  {
    if(x[i]%2==0)
      ret++;
    else
      ret--;
  }
    return ret;
}


int main ()
{
  N = __VERIFIER_nondet_int();
  if (N > 1) {
    int x[N];
    int temp;
    int ret;
    int ret2;
    int ret5;
  
    ret = fun(x);

    temp=x[0];x[0] = x[1]; x[1] = temp;
    ret2 = fun(x);
    temp=x[0];
    for(int i =0 ; i<N-1; i++){
       x[i] = x[i+1];
    }
    x[N-1] = temp;
    ret5 = fun(x);

    if(ret != ret2 || ret !=ret5){ 
      {reach_error();}
    }
  }
  return 1;
}