#include <bits/stdc++.h>

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n; cin >> n;
  if (n == 0) {
    cout << 0 << endl;
    return 0;
  }
  cout << "0.";
  for (int i = 0; i < n; i++) {
    switch (i % 6) {
      case 0: cout << 1; break;
      case 1: cout << 4; break;
      case 2: cout << 2; break;
      case 3: cout << 8; break;
      case 4: cout << 5; break;
      case 5: cout << 7; break;
    }
  }
  cout << endl;
  return 0;
}