a,b = map(int,input().split())

# abab aaaaa (x個, 残り(y-x)個)
# XY YX XY YX 4個. 2x + (y-x) X 1Y 2X 3Y ということで, (2(y-x) - 1)個.

print(max(0, 2 * (max(a,b) - min(a,b)) - 1) + 2 * min(a, b))