import sys

sys.setrecursionlimit(10 ** 8)

input = sys.stdin.readline


def main():
    A, B = [int(x) for x in input().split()]

    ans = 0

    p = -1
    while not (A == 0 and B == 0):
        if A > B:
            A -= 1
            if p == 1:
                ans += 1
            p = 0
        else:
            B -= 1
            if p == 0:
                ans += 1
            p = 1

    print(ans)


if __name__ == '__main__':
    main()