#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;
}