#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import fractions
import itertools


def main():
    fs = [fractions.Fraction(1, x) for x in (int(input()) for _ in range(3))]
    ans = 0
    for x, y in itertools.combinations(fs, 2):
        ans = max(ans, 1 / abs(x - y))
    print("{}/{}".format(ans.numerator, ans.denominator))


if __name__ == '__main__':
    main()