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])
	}
	sort.Sort(sort.Reverse(sort.IntSlice(A)))

	var sum int
	for i := 0; i < K; i++ {
		if A[i] <= 0 {
			break
		}
		sum += A[i]
	}

	fmt.Println(sum)
}