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

int main(){
    ll k;
    double ans = 0;
    cin >> k;
    for(int i = 1; i < 500000; i++){
        ans += sin(k * i) /  pow(i, i);
    }
    printf("%.15lf\n", ans);
}