import sys
input = sys.stdin.readline

# from collections import deque

def linput(_t=int):
    return list(map(_t, input().split()))

def gcd(n,m):
    while m: n,m = m, n%m
    return n

def lcm(n,m): return n*m//gcd(n,m)

def main():
    # N = int(input())
    N,K = linput()
    vA = linput()
    # vE = [linput() for _ in [0,]*M]

    vA.sort()
    res = 0

    cnt = 0
    for a in vA[::-1]:
        if a>0 and cnt<K:
            cnt += 1
            res += a

    print(res)

    # print(("No","Yes")[res%2])


main()