#include <bits/stdc++.h>
using namespace std;
int n;
int len, a[40005];
int main()
{
    cin >> n;
    // 高精度的数初始化为 1
    len = 1;
    a[0] = 1;
    // 每次乘以 t
    for (int t = 1; t <= n; t++)
    {
        for (int i = 0; i <= len - 1; i++)
            a[i] *= t;
        for (int i = 0; i <= len - 2; i++)
        {
            a[i + 1] += a[i] / 10;
            a[i] %= 10;
        }
        while (a[len - 1] >= 10)
        {
            a[len] = a[len - 1] / 10;
            a[len - 1] %= 10;
            len++;
        }
    }
    for (int i = len - 1; i >= 0; i--)
        cout << a[i];
    return 0;
}