Identical Toys Distribution

Given the number of T identical toys, find the number of ways W to distribute them among N children. 

Input Format: 

The first line will contain T and N separated by a space. 

Output Format: 

The first line will contain W. As W can be large, print the answer as modulo 1000000007 

Boundary Conditions: 1 <= T, N <= 1000 

Example Input/Output 1: 

Input:

2 2 

Output:

3 

Explanation: The three ways to disribute 2 toys among 2 children are (2,0) (0,2) (1,1)

Source Code:

from math import factorial

t,n=[int(i) for i in input().split()]

r=t+n-1

r1,r2,r3=factorial(r),factorial(t),factorial(r-t)

print((r1//(r2*r3))%1000000007)