There is a robot on an `m x n` grid. The robot is initially located at the top-left corner (i.e., `grid[0][0]`). The robot tries to move to the bottom-right corner (i.e., `grid[m - 1][n - 1]`). The robot can only move either down or right at any point in time.
Given the two integers `m` and `n`, return the number of possible unique paths that the robot can take to reach the bottom-right corner.
The test cases are generated so that the answer will be less than or equal to `2 * 10^9`.
### Constraints
- `1 <= m, n <= 100`
### Input Format
A single line containing two space-separated integers `m` and `n`.
### Output Format
Print the number of unique paths.
Sample Cases
Example 1Sample Case
Input: 3 7
Output: 28
Example 2Sample Case
Input: 3 2
Output: 3
Example 3Sample Case
Input: 3 3
Output: 6
Constraints
Runtime Limit: 2000 ms per test batch
Memory Limit: 256 MB
Standard I/O stream reading
Official submissions are evaluated against hidden test cases on the server to verify time & memory complexity.