#include <iostream>
#include <utility>
#include <fstream>
#include <cmath>

using namespace std;

static const double PI = 3.141592653589793238462643383;

pair<int, int> solve(double r)
{
	for (int lower = 1; ; ++lower) {
		const int upper = (int)(PI * lower);
		if (PI - (double)upper / lower < r){
			return make_pair(upper, lower);
		} else if ((double)(upper + 1) / lower - PI < r) {
			return make_pair(upper + 1, lower);
		}
	}
}

int main()
{
	//ifstream cin("pi.in.txt");
	double r;
	while (cin >> r && r != 0){
		const pair<int, int> answer = solve(r);

		cout << answer.first << "/" << answer.second << endl;
		//cout << "=" << abs((double)answer.first / answer.second - PI) << endl;
	}
}