from fractions import Fraction


def frac_lcm(n0, d0, n1, d1):
    def lcm(a, b):
        def gcd(x, y):
            if x > y:
                return gcd(y, x)
            if x == 0:
                return y
            return gcd((y - x) % x, x)
        return a * b / gcd(a, b)
    return Fraction(lcm(n0 * d1, n1 * d0), d0 * d1)

T = []
for i in range(3):
    T.append(input())
ans = min(frac_lcm(n0, d0, n1, d1)
          for (n0, d0) in [(T[0] * T[1], (T[1] - T[0])),
                           (T[0] * T[1], (T[1] + T[0]))]
          for (n1, d1) in [(T[0] * T[2], (T[2] - T[0])),
                           (T[0] * T[2], (T[2] + T[0]))])
print('%d/%d' % (ans.numerator, ans.denominator))