Alice and Bob Flower Game

Alice and Bob play a flower-picking game with n type-A flowers and m type-B flowers arranged in a line. On each turn, a player picks one flower from either end. The player who picks the last flower wins. Count the number of arrangements where Alice wins with optimal play.

Examples
Input: [3,2]
Output: 10
Hints

Alice and Bob Flower Game

Alice and Bob play a flower-picking game with n type-A flowers and m type-B flowers arranged in a line. On each turn, a player picks one flower from either end. The player who picks the last flower wins. Count the number of arrangements where Alice wins with optimal play.