#include <iostream>
#include <vector>
#include <cmath>
#include <fstream>

#define EPS 1e-10

using namespace std;

typedef long long ll;
main()
{
	ifstream cin("A.txt");
	double d;
	while(cin>>d && d>EPS)
	{
		ll b;
		for(b=1; ; b++)
		{
			ll a1 = (ll)(b*M_PI);
			ll a2 = a1+1;
			double x1 = M_PI-(double)a1/b;
			double x2 = (double)a2/b-M_PI;
			if(x1 < d && x2>=d)
			{
				cout << a1 << '/' << b << endl;
				break;
			}
			else if(x2<d && x1>=d)
			{
				cout << a2 << '/' << b << endl;
				break;
			}
			else if(x1<d && x2<d)
			{
				if(x1<x2)
					cout << a1 << '/' << b << endl;
				else
					cout << a2 << '/' << b << endl;
				break;

			}
		}
	}
	return 0;
}