#include <bits/stdc++.h>
#define rep(i, a, n) for (int i = a; i < n; i++)
#define repr(i, a, n) for (int i = n - 1; i >= a; i--)
using namespace std;
using ll = long long;
using P = pair<int, int>;
template <typename T> void chmin(T &a, T b) { a = min(a, b); }
template <typename T> void chmax(T &a, T b) { a = max(a, b); }

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);

  string a;
  cin >> a;
  stringstream ss;
  ss << setfill('0') << left << setw(6) << a;
  string p = ss.str().substr(2);
  int ip = stoi(p)*1000;

  double ans = ip / (10000000.0 - ip);
  cout << fixed << setprecision(10) << ans << endl;
}