X, Y = map(int, input().split()) Z_1 = (int(X+Y))/2 Z_2 = (int(X+Y))/2 - 6 Z_3 = (int(X+Y))/2 + 6 if Z_2 < 0: Z = Z_3 print(Z) else: if X-Z_1 < X-Z_2: Z = Z_2 print(Z) else: Z = Z_1 print(Z)