def dfs(a, b, prev):
    if a == 0 and b == 0:
        return 0

    else:
        ret = 0

        if a > 0:
            d = 1 if prev != 0 else 0
            ret = max(ret, dfs(a - 1, b, 0) + d)

        if b > 0:
            d = 1 if prev != 1 else 0
            ret = max(ret, dfs(a, b - 1, 1) + d)

        return ret


a, b = map(int, input().split())
print(max(dfs(a - 1, b, 0), dfs(a, b - 1, 1)))