#include<stdio.h>

int fact(int n);

int main() {
    printf(" factorial is : %d",fact(5));
    return 0;
}

int fact(int n)  {
    if(n==0)    {
        return 1;
    }
    int factNm1=fact(n-1);
    int factN= factNm1*n;
    return factN;
}