import sys

sys.setrecursionlimit(10 ** 7)
f_inf = float('inf')
mod = 10 ** 9 + 7


def resolve():
    n, k = map(int, input().split())
    A = sorted(list(map(int, input().split())), reverse=True)

    res = A[0]
    for i in range(1, k):
        if A[i] > 0:
            res += A[i]

    print(res)


if __name__ == '__main__':
    resolve()