#include<bits/stdc++.h>
//#include<atcoder/all>

using namespace std;
//using namespace atcoder;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
#define rep(i,n) for(ll i = 0;i < (ll)n;i++)
#define ALL(x) (x).begin(),(x).end()
#define MOD 1000000007



int main(){
  
  cout << fixed << setprecision(20);
  int k;
  cin >> k;
  double res = 0;
  for(int i = 1;i <= 10;i++){
    ll x = 1;
    rep(j,i)x *= i;
    res += sin(i*k)/x;
  }
  cout << res << "\n";


  return 0;
}