#920. Paths in a grid
In an m×n grid, how many paths go from the top-left corner to the bottom-right corner if you can only move right or down?
### Input
One line: m n (1 ≤ m, n ≤ 30).
### Output
A number.
Examples
Input
23 19
Output
113380261800
Input
25 2
Output
25
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.