import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

a, b = map(int, readline().split())
if a < b:
    a, b = b, a
ans = -1
for i in range(a + b + 1):
    if i % 2 == 0:
        if a > 0:
            ans += 1
            a -= 1
        else:
            break
    else:
        if b > 0:
            ans += 1
            b -= 1
        else:
            break
print(ans)