#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("Yes");}else{puts("No");}
#define MAX_N 200005

int main() {
    int n;
    cin >> n;

    string s = "142857";

    cout << 0;
    if(n > 0){
        cout << '.';
        rep(i,n){
            cout << s[i%6];
        }
    }
    cout << endl;
    
    return 0;
}