#include<stdio.h>
long long int factorial(int n)
{
    if(n==0||n==1)
    {
        return 1;
    }
    else{
        return n * factorial(n-1);
    }
}
int main()
{
    int n;
    print("enter an integer (between -10 and 10): ")
    scanf("%d", &n);
    if(n<0){
        printf("Invalid Input\n");
    }
    else if(n>10){
        printf("Input out of rangr for accurate calculation (max 10 for long long int).\n");
    }else{
        long long int result= factorial(n);
        printf("the factorial of %d is %11d\n", n, result);
    }
}