#include <iostream>
#include <thread>
#include <vector>
using namespace std;

int times(int x){
    int r = 1;
    for(int i = 2; i <= x; i++) r *= i;
    return r;
}

void sum_to_n(int n, int& result){
    int tmp = 0;
    for(int i = 1; i <= n; i++) tmp += i;
    result = tmp;
}

void fact_table(int n, vector<int>& out){
    out.resize(n);
    for(int i = 1; i <= n; i++){
        out[i-1] = times(i);
    }
}

int main(){
    int n;
    cin >> n;

    int sum;
    vector<int> facts;
    int fn;
    
    thread t1(sum_to_n, n, ref(sum));
    thread t2(fact_table, n, ref(facts));
    thread t3([&](){ fn = times(n); });

    t1.join();
    t2.join();
    t3.join();

    cout << sum << endl;
}