Problem Statement:
Ahmad is a mathematics scientist, he has many researches and papers on counting theory, he is working now on a new project and he needs your help to calculate the number of paths in a rectangular grid to move from the upper-left corner to bottom-right corner. He can move only down and right.


Input Format:
The input consist of many cases, each case contains two numbers 0<n, m<=100 the number of rows and columns in the grid respectively, input ends when n=m=-1


Output Format:
For each case print one line the number of paths MOD 1000000007


Sample Input:
1 2 2 2 -1 -1


Sample Output:
3 6


Notes:
Explanation of the second case:






Added by: feras_kassar
Added at: 2014-05-19 20:19:42 UTC
Time Limit: 2 seconds
Partial score: No
Source:Tishreen-CPC 2014