#include <cstdlib>
#include <iostream>

using namespace std;

int main(int argc, char *argv[])
{
    int n;
    int sum = 1;
   
    while (cin >> n)
    {     
    for (int i=1;i<=n;i++)    
    sum = sum*i;
     
    cout << sum << endl;
    sum=1;
    }
    //system("PAUSE");
    return EXIT_SUCCESS;
}