# Framework: Standard Library
# Technology Stack: N/A

m, k = map(int, input().split())
abc = 0
abc = (k + 1) * m + (m + 1) * k + 2 * (k // 2) + 2 * (m // 2) + (k % 2 + m % 2) % 2
abc = min(abc, (k + 1) * m + (m + 1) * k + (m - 1) * k + (k - 1) * m)
print(abc)