def main():

    for _ in range(int(input())):
        N, M = map(int, input().split())
        A = list(map(int, input().split()))

        before = M
        before2 = 0
        for a in A:
            if a - before2 < 0 or a - before2 > before:
                print("No")
                break

            before, before2 = a, before - (a - before2)
        else:
            print("Yes")


if __name__ == "__main__":
    main()