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n, k = map(int, input().split()) a = [] for i in range(n): a.append([]) for j in range(k): a[i].append(1) for i in range(n - 1): for j in range(k - 1): a[i + 1][j + 1] = a[i + 1][j] + a[i][j + 1] print(a[n - 1][k - 1] % ((10 ** 6) + 7))