/* -*- coding: utf-8 -*-
 *
 * 746.cc:  No.746 7の倍数 - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int N = 6;
const char ds[] = "142857";

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  putchar('0');
  if (n > 0) {
    putchar('.');
    for (int i = 0; i < n; i++) putchar(ds[i % N]);
  }
  putchar('\n');
  return 0;
}