#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++)
#define ALL(x) (x).begin(), (x).end()

const double PI = acos(-1);

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

  int n;
  cin >> n;

  int r = 1;
  string s = "0";
  REP (i, n) {
    r = 10 * r;
    if (s.size() == 1)
      s += ".";
    s += char('0' + r / 7);
    r %= 7;
  }

  cout << s << endl;
  
  return 0;
}