wilson's thorem implemt in C

wilson's thorem implemt in C

#include<stdio.h>
int main()
{
      int n,m,i,p,fact;
      while(scanf("%d",&n)==1){
            fact=1;
            m=n;
                  for(i=1;i<=n-1;i++){
                   fact=(fact*i) %m;
                  }

                  if (fact==n-1)
                  printf("%d is prime\n",n);
                  else
                  printf("%d is not prime\n",n);
      }
      return 0;
}