Dynamic ProgrammingMathGrid DP
A robot stands in the top-left corner of an m x n grid and wants to reach the bottom-right corner. It can only move right or down. How many different paths are there?
Input
A single line with m and n.
Output
Print the number of unique paths.
Constraints
1 <= m, n <= 18
Example 1
Input
3 7
Output
28
There are 28 distinct paths.
Example 2
Input
3 2
Output
3
Three paths: RDD, DRD, DDR.