#include<iostream>
using namespace std;

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

    int a[] = {1,4,2,8,5,7};
    
    if (n == 0){
        cout << "0\n";
        return 0;
    }

    cout << "0.";
    for (int i=0; i < n; i++){
        cout << a[i % 6];
    }
    cout << "\n";

}