MOD = 10**9 + 7
n,m = map(int,input().split())
lst = [[0]*(m+1)for _ in range(n+1)]
lst[1][1] = 1
for i in range(1,n+1):
    for j in range(1,m+1):
        if i ==1 and j ==1:
            continue
        lst[i][j] = (lst[i-1][j] + lst[i][j-1])%MOD
print(lst[n][m])