#include <iostream>
using namespace std;
int main(void){
    // Your code here!
    int n;
    cin>>n;
    if(n==0){cout<<0<<endl;return 0;}
    cout<<"0.";
    string s="142857";
    for(int i=0;i<n/6;i++){
        cout<<s;
    }
    cout<<s.substr(0,n%6)<<endl;
}