a,b,c = STDIN.map(&:to_i)
tmp = a.lcm(b.lcm(c))
a = tmp / a
b = tmp / b
c = tmp / c
[a,b,c].max.downto(2){|i|
    if a % i == b % i && b % i == c % i
        tmp2 = tmp.gcd(i)
        puts "#{tmp / tmp2}/#{i / tmp2}"
        exit
    end
}
puts "#{tmp}/1"