#include <iostream>
using namespace std;
int Factorial( const int num )
{
int t = 1;
int total = 1;
while( t <= num ) {
total = total * t;
t++;
} // end while
cout << total;
return total;
}
int main () {
int number;
int total;
cin >> number;
Factorial (number);
return 0;
}