day2_7.cpp

#include<iostream>
int factorial(int n)
{
    if(n==1)
    {
        return 1;
    }
    else if(n>1)
    {
        return n*factorial(n-1);
    }
}

int main()
{
    int n;
    scanf("%d",&n);
    printf("%d", factorial(n));
    return 0;
}