Given two positive integers row_count and column_count representing the dimensions of a grid, compute the number of distinct paths from the cell (0, 0) to the cell (row_count - 1, column_count - 1), where at each step you may move either one cell right or one cell down.
Example 1
Input: row_count=4, column_count=5
Output: 35
Explanation: There are 35 unique paths from (0,0) to (3,4) moving only right or down.
Example 2
Input: row_count=2, column_count=4
Output: 4
Explanation: There are 4 unique paths from (0,0) to (1,3) moving only right or down.
Constraints
Case 1
Input: row_count=5, column_count=3
Expected: 15
Case 2
Input: row_count=6, column_count=2
Expected: 6
Case 3
Input: row_count=1, column_count=10
Expected: 1
Case 4
Input: row_count=10, column_count=1
Expected: 1