Walking Home Separately

Tosuni and Tojuni had a big fight and now want to walk home separately.

Tosuni and Tojuni move on a two-dimensional grid of $N$ rows and $M$ columns, and they can only move right or down.

Let $(i, j)$ be the position reached from $(1, 1)$ by moving down $i-1$ cells and right $j-1$ cells.

The couple starts at $(1, 1)$ and moves one cell at a time at the same moment until they reach their home at $(N, M)$.

During this walk, they want to avoid meeting in the same cell, except at the starting point and at the destination (home).

Find the number of ways the couple can walk home.

The first line contains integers $N$ and $M$ separated by a space. ($2 \le N, M \le 200\\,000$)

Print the number of ways the couple can walk home, modulo $10^9+7$. ($10^9+7$ is a prime number.)