package main

import . "fmt"
import . "sort"

func main() {
	var n,k int
	Scan(&n,&k)
	a:=make([]int,n,n)
	for i:=range a {
		Scan(&a[i])
	}
	Ints(a)
	var s int
	for i:=0;i<k;i++ {
		x:=a[n-1-i]
		if x>0 {
			s+=x
		}
	}
	Println(s)
}