!n

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll origins=1;
ll factorial(ll n){
    ll sum=origins;
    for(ll i=1;i<=n;i++){
        sum*=i;
    }
    return sum;
}
int main(){
    int n;
    scanf("%d",&n);
    printf("%d",factorial(n));
}