m, n = map(int, input().split())
d = [1]*(m+1)
if m==1 or n==1:
    print(1 %(10**9+7))
else:
    for i in range(2,n+1):
        for j in range(2,m+1):
            d[j]=d[j]+d[j-1]
    print(d[m]%(10**9+7))