import streams, sequtils, strutils, algorithm, math, future, sets, tables, hashes
proc `ceilDiv`*[T](x, y: T): T = x div y + ord(x mod y != 0)
proc `//=`*(x: var SomeInteger; y: SomeInteger) = x = x div y
proc `%=`*(x: var SomeInteger; y: SomeInteger) = x = x mod y

var
    L = stdin.readLine.split.map(parseInt)
    N = L[0]
    K = L[1]
    A = stdin.readLine.split.map(parseInt)
    ans = 0
    cnt = 0
A = A.sortedByIt(-it)
for i in 0..<K:
    if A[i] > 0:
        ans += A[i]
        inc cnt
if cnt == 0:
    ans += A[0]
echo ans