package main

import (
	"fmt"
	"sort"
)

func main() {
	var n, k int
	fmt.Scan(&n, &k)

	a := make([]int, n)
	for i := range a {
		fmt.Scan(&a[i])
	}
	sort.Ints(a)

	ans := 0
	for i := n - 1; i >= 0; i-- {
		j := n - 1 - i
		if a[i] < 0 {
			break
		}
		if j+1 > k {
			break
		}
		ans += a[i]
	}
	fmt.Println(ans)
}