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)