#include <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <math.h>
#include <cmath>
#include <limits.h>
#include <map>
#include <unordered_map>
#include <set>
#include <queue>
#include <algorithm>
#include <functional>
#include <stdio.h>
using namespace std;

long long MOD = 1000000007;

int main() {

    int N;
    cin >> N;

    string S = "142857";

    if ( N == 0 ) { cout << 0 << endl; return 0; }

    string ans = "0.";

    for ( int i = 0; i < N; i++ ) {
        ans += S[i%6];
    }

    cout << ans << endl;


    return 0;
}