#include <iostream>
using namespace std;
int Factorial(int n)
{
if (n == 0)
return 1;
else
return n*Factorial(n - 1);
}
int main()
{
int num;
cin >> num;
cout << Factorial(num) << '\n';
return 0;
}
#include <stdio.h>
int Factorial(int n)
{
if (n == 0)
return 1;
else
return n*Factorial(n - 1);
}
int main(void)
{
int num;
scanf("%d", &num);
printf("%d \n", Factorial(num));
return 0;
}