def nwd(a, b) if b==0 return a end return nwd(b, a%b) end while true begin x = gets.split rescue break end u1 = x[0].split('/') o = x[1].split('/') u2 = x[2].split('/') l= u1.split('/') m= u1.split('/') l1 = l[0].to_i l2 = l[1].to_i m1 = m[0].to_i m2 = m[1].to_i m3 = m1*m2 if o == '+' l3 = l1*m2 + l2*m1 elsif o == '-' l3 = l1*m2 - l2*m1 elsif o == '*' l3 = l1*l2 else: l3 = l1*m2 m3 = l2*m1 end dzielnik = nwd(l3, m3) jeden = l3/dzielnik jeden = jeden.to_s dwa = m3/dzielnik dwa = dwa.to_s puts jeden + '/' + dwa end