H, W = map(int, input().split())
d = abs(W)
if H == 0 or d == 0:
    print(0)
else:
    total = 0
    for i in range(H):
        current_H = H - i
        if current_H >= d:
            total += 1
        else:
            total += 2 * (d - current_H)
    print(total)