#include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <algorithm>
#include <utility>
#include <queue>
#include <set>
#include <map>
#include <deque>
#include <iomanip>
#include <cstdio>

using namespace std;
typedef  long long ll;
typedef pair<int,int> PII;
typedef vector<int> VI;
typedef vector<VI> VVI;
#define  MP make_pair
#define  PB push_back
#define inf  1000000007
#define rep(i,n) for(int i=0;i<(int)(n);++i)

int a[] = {1,4,2,8,5,7};

int main(){
    int n;
    cin >> n;
    if(n==0){
        cout << 0 << endl;
        return 0;
    }
    cout << "0.";
    rep(i,n){
        cout << a[i%6];
    }
    cout << endl;
    return 0;
}