4-4

#include<stdio.h>
int main(void)
{
    int i,m;
    printf("Enter a number:");
    scanf("%d",&m);
    for(i=2;i<=m/2;i++)
        if(m%i==0)
            break;
        if(i>m/2&&m!=1)
            printf("%d is a prime number!\n",m);
        else
            printf("No!\n");

        return 0;

}