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, v := range a {
		if v < 0 && i != n-1 {
			continue
		}
		if n-i <= k {
			ans += v
		}
	}
	fmt.Println(ans)
}