#include<bits/stdc++.h>
using namespace std;
int a[11]={1,1,2,6,24,120,720,5040,40320,362880,3628800};
int main(){
	scanf("%d",&a[0]);
	printf("%d",a[a[0]]);
	return 0;
}
/**************************************************************
	Problem: 1004
	User: chenxurui
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/