import sequtils,strutils,algorithm
var
    N,K,ans : int
    A : seq[int]


(N, K) = stdin.readline.split.map(parseInt)
A = stdin.readline.split.map(parseInt)
A.sort(system.cmp)
A.reverse
var K2 = K
for a in A:
    if a > 0 and K > 0:
        ans += a
        K -= 1
    else:
        break
if K2 == K:
    ans += A[0]

echo ans