#include<bits/stdc++.h>
using namespace std;

int a[120],b[120],n;
void add(int *a , int *b){
    for(int i = 1;i <= 120;i++){
        int c;
        b[i] += a[i] + c;
        c = b[i] / 10;
        b[i] %= 10;
    }
}
void cheng(int *a , int c){
    for(int i = 1;i <= 120;i++){
        int b;
        a[i] *= c + b;
        c = a[i] / 10;
        a[i] %= 10;
    }
}

int main(){
    scanf("%d",&n);
    a[1] = 1;
    for(int i = 1;i <= n;i++){
        cheng(a , i);
        add(a , b);
    }
    bool flag = 0;
    for(int  i = 120;i >= 1;i--){
        if(b[i] != 0){
            flag = 1;
        }
        if(flag){
            printf("%d",b[i]);
        }
    }
    return 0;
}