t1 = gets.chomp.to_i
t2 = gets.chomp.to_i
t3 = gets.chomp.to_i

x = t1*(t3-t2)
y = t3*(t2-t1)
g = x.gcd(y)
N = y/g

u = N*t1*t2
d = t2-t1
g = u.gcd(d)
u /= g
d /= g

print u, "/", d, "\n"