#include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)n - 1; i > -1; i--)
#define all(x) (x).begin(), (x).end()
#define ll long long
#define ld long double
#define INF 1000000000000000000
typedef pair<ll, ll> pll;

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

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

    int first = 10;
    cout << "0.";
    rep(i, N) {
        char ans = first / 7 + '0';
        first = (first % 7) * 10;
        cout << ans;
    }
    cout << endl;
}