#include<stdio.h>
int isPrime(int,int);
int main(){
int num,prime;
printf("Enter a positive number: ");
scanf("%d",&num);
prime = isPrime(num,num/2);
if(prime==1)
printf("%d is a prime number",num);
else
printf("%d is not a prime number",num);
return 0;
}
int isPrime(int num,int i){
if(i==1){
return 1;
}else{
if(num%i==0)
return 0;
else
isPrime(num,i-1);
}
}