/* 
 * Program to Check Whether a Number is Prime or Not 
 */

#include <stdio.h>

/* Entry point to program */
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;
}