#include <bits/stdc++.h> using namespace std; int main(){ cout << fixed << setprecision(10); int k; cin >> k; double ans = 0; for (int i = 1; i <= 10; i++){ double tmp = sin(k * i); for (int j = 0; j < i; j++){ tmp /= i; } ans += tmp; } cout << ans << endl; }