#include<stdio.h>
int main()
{
	int num=0, flag = 1,i;

	while(num <= 0)
	{
		printf("Enter an integer: ");
		scanf("%d",&num);
		if(num <= 0)
			printf("Invalid inpur, enter a positive integer.\n");
	}

	if(num == 1 || num == 2)
	{
		flag = 0;
	}
	else
	{
		flag = 0;
		for(i=2;i<=num/2;i++)
		{
			if(num%i == 0)
			{
				flag = 1;
				break;
			}
		}
	}
	
	if(flag == 0)
		printf("%d is a prime number\n",num);
	else
		printf("%d is not a prime number\n",num);
}