from sys import stdin
def main():
    #入力
    readline=stdin.readline
    N,K=map(int,readline().split())
    A=list(map(int,readline().split()))

    A.sort(reverse=True)
    c=0
    res=0
    for i in range(N):
        if A[i]>0:
            c+=1
            res+=A[i]
        if c==K:
            break
    if c==0:
        res+=A[0]
    print(res)

if __name__=="__main__":
    main()