def main():
    N, K = map(int, input().split())
    A = list(map(int, input().split()))

    A_positive = filter(lambda num: num > 0, A)
    A_positive = sorted(A_positive, reverse=True)

    if len(A_positive) < K:
        print(sum(A_positive))
    else:
        print(sum(A_positive[:K]))


if __name__ == "__main__":
    main()