n,k = list(map(int, input().split()))
a = list(map(int, input().split()))
a.sort(reverse=True)
count = 0
ans = 0
for i in a:
    if(i>=1 and count<k):
        count+=1
        ans+=i
    if(i<=0):
        break
#print(a)
print(ans)
print()