import sys
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
a,b = map(int,readline().split())
if a < b:
    a,b = b,a
a -= 1
ans = 0
while b != 0:
    ans += 1
    b -= 1
    if a == 0:
        break
    ans += 1
    a -= 1
print(ans)