Ride me, the big turtle!#5104

Ride me, the big turtle!

1 second

128 megabytes

Easy

A turtle is located in the upper-left cell $(1, 1)$ of a grid. The turtle can move either one cell down or one cell to the right at each step.

In how many different ways can the turtle reach the cell $(n, m)$ ?

Input

The only line contains two integers $n$ and $m$ ( $1 \leq n, m \leq 50$ 1 \leq n, m \leq 50 ).

Print the number of ways to reach the cell $(n, m)$ .

Example 1

Loading

Example 2

Loading

1 \leq n, m \leq 50