#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
main(){
    int N;
    cin >> N;
    string S = "142857";
    if(!N)cout << 0 << endl;
    else{
        cout << "0.";
        rep(i,0,N)cout << S[i % 6];
        cout << endl;
    }
}