#import numpy as np
import sys
from collections import defaultdict
read = sys.stdin.buffer.read
readline = sys.stdin.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(100)

n , k = map(int,input().split())
A = list(map(int,input().split()))

fruit = sorted(A , reverse= True)
delicious = 0
index = 0
number_fruit = 0
while  number_fruit < k and index < n:
    if fruit[index] > 0 :
        delicious += fruit[index]
        number_fruit += 1
    else:
        break
    index += 1

print(delicious)