#include <queue>
#include <math.h>
#include <stack>
#include <stdio.h>
#include <iostream>
#include <vector>
#include <iomanip>
#include <string.h>
#include <algorithm>
using namespace std;
#define LL long long
const int N = 1e4 + 10;
const int INF = 0x3f3f3f3f;
long long len = 1 , a[N];
void mul(long long x)
{
	for(int i = 0 ; i < len ; i++)
		a[i] *= x;
	for(int i = 0 ; i < len ; i++)
	{
		a[i+1] += a[i]/10000;
		a[i] %= 10000;
	}
	while(a[len] != 0)
	{
		a[len+1] = a[len]/10000;
		a[len] %= 10000;
		len++; 
	}
}
int main()
{
	int n;
	cin >> n;
	a[0] = 1;
	for(int i = 2 ; i <= n ; i++)
		mul(i);
	len--;
	cout << a[len];
	for(int i = len-1; i >= 0 ; i--)
		printf("%04d",a[i]);
	return 0;
}