// Unique Paths — MEDIUM

// Category: dynamic-programming

There is a robot on an `m x n` grid. The robot starts at the top-left corner and tries to reach the bottom-right corner.

The robot can only move **right** or **down** at any time.

Given the two integers `m` (rows) and `n` (columns), return the **number of unique paths** the robot can take.

Example: m = 3, n = 7

Output: 28