// No.1046 Fruits Rush
package main

import (
	"fmt"
	"sort"
)

func main() {
	var n, k int
	fmt.Scan(&n, &k)
	a := make([]int, n)
	for i := 0; i < n; i++ {
		fmt.Scan(&a[i])
	}
	ans := 0
	sort.Sort(sort.Reverse(sort.IntSlice(a)))
	for j := 0; j < n; j++ {
		if a[j] <= 0 {
			break
		}
		if (j + 1) <= k {
			ans += a[j]
		}
	}
	fmt.Println(ans)
}