#include "bits/stdc++.h"

using namespace std;

typedef pair<int, int> P;
#define int long long
#define ll long long
#define mod 1000000007
#define INF (1LL<<60)

#define rep(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)




signed main(){

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

	if (N == 0){
		cout << "0" << endl;
		return 0;
	}
	cout << "0.";
	for (int i = 0; i < N; i++){
		cout << a[i % 6];
	}

	return 0;
}