#include<iostream>
using namespace std;
int n,a[]={1,4,2,8,5,7};
main()
{
	cin>>n;
	if(n==0)
	{
		cout<<0<<endl;
		return 0;
	}
	cout<<"0.";
	for(int i=0;i<n;i++)cout<<a[i%6];
	cout<<endl;
}