#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define llong long long

int main() {
    int n;
    cin >> n;
    string s = "142857";

    if(n == 0) {
        cout << 0 << "\n";
    } else {
        cout << "0.";
        rep(i, n / 6) cout << s;
        rep(i, n % 6) cout << s[i];
        cout << "\n";
    }
}