/*
AizuOnline A0000
Title
*/
#include <stdio.h>
// Select Below
//#include <stdlib.h>
//#include <string.h>
//#include <float.h>
//#include <math.h>
//#include <limits.h>
//Global data section
int n;


int primes[]={2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,
	      101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,
	      211,223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,
	      307,311,313,317,331,337,347,349,353,359,367,373,379,383,389,397,
	      401,409,419,421,431,433,439,443,449,457,461,463,467,479,487,491,499,
	      503,509,521,523,541,547,557,563,569,571,577,587,593,599,
	      601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,
	      701,709,719,727,733,739,743,751,757,761,769,773,787,797,
	      809,811,821,823,827,829,839,853,857,859,863,877,881,883,887,
	      907,911,919,929,937,941,947,953,967,971,977,983,991,997};


//
int isprime(int n)
{
  int i;
  for(i=0;i<sizeof(primes)/sizeof(int);i++)
    if(n == primes[i])
      return(-1);
  else if(n % primes[i] ==0)
      return(0);
  return(-1);
}
int main()
{
  int i;
  int cnt;

  while(EOF != scanf("%d",&n) && n)
    {

      cnt=0;
      for(i=2;i<=n-1;i++)
	{
	  //printf("i:%d %d %d %d\n",i,isprime(i),n-i,isprime(n-i));
	cnt += ((isprime(i)&&isprime(n+1-i))?1:0);
	}
      printf("%d\n",cnt);

    }

return(0);
}