#include <stdio.h> int main() 
{ int n, i, flag = 0; printf("Enter a positive integer: "); 
scanf("%d", &n); for (i = 2; i <= n / 2; ++i) {
 // condition for non-prime if (n % i == 0) { flag = 1; break; } } 
if (n == 1) { printf("1 is neither prime nor composite."); } 
else { if (flag == 0) printf("%d is a prime number.", n);
 else printf("%d is not a prime number.", n); } return 0; }
