Once Bob got to a sale of old TV sets. There were n TV sets at that sale. TV set with index i costs ai bellars. Some TV sets have a negative price — their owners are ready to pay Bob if he buys their useless apparatus. Bob can «buy» any TV sets he wants. Though he's very strong, Bob can carry at most m TV sets, and he has no desire to go to the sale for the second time. Please, help Bob find out the maximum sum of money that he can earn.

Input

The first line contains two space-separated integers n and m (1 ≤ m ≤ n ≤ 100) — amount of TV sets at the sale, and amount of TV sets that Bob can carry. The following line contains n space-separated integers ai ( - 1000 ≤ ai ≤ 1000) — prices of the TV sets. 

Output

Output the only number — the maximum sum of money that Bob can earn, given that he can carry at most m TV sets.

Examples

Input

5 3
-6 0 35 -2 4


Output

8


Input

4 2
7 0 0 -7


Output

7
import java.awt.Point;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;
import java.util.StringTokenizer;

public class A {

    public static void main(String[] Args) throws IOException {
        new A().solve();
    }

    int o = INF;
    int n;
    static int[] dx_ = { 0, 0, 1, -1 };
    static int[] dy_ = { 1, -1, 0, 0 };

    void solve() throws IOException {
        int n = si(), m=si(), a[] = sai(n);
        Arrays.sort(a);
        int x = 0; 
        for (int i = 0; i < m; i++) {
            if (x+a[i] < x) x+= a[i];
        }
        x*=-1;
        System.out.println(x);
    }

    String[] toStr = new String[5 + (int) 1e6];
    HashMap<String, Integer> toInt = new HashMap<String, Integer>();

    class num {
        char[] cs = new char[(int) 1e4];
        int size = 1;

        public num() {
            cs[0] = 'A';
            toStr[1] = "A";
        }

        void inc() {
            inc(cs, 0);
        }

        int inc(char[] cs, int p) {
            if ('A' <= cs[p] && cs[p] <= 'Z')
                cs[p]++;
            else {
                cs[p] = 'A';
                size++;
            }
            if (cs[p] > 'Z') {
                cs[p] = 'A';
                p++;
                inc(cs, p);
            }
            return p;
        }

        @Override
        public String toString() {
            String s = "";
            for (int i = size - 1; i >= 0; i--) {
                s += cs[i];
            }
            return s;
        }
    }

    /**
     * important for speed!!! PrintWriter out=new PrintWriter(new
     * OutputStreamWriter(System.out)); out.close();
     * 
     * @param v
     */
    void dfs(LinkedList<Integer> v) {
        if (ok(v)) {
            o = Math.min(o, n - v.size());
        } else {
            LinkedList<Integer> first = new LinkedList<Integer>(v);
            LinkedList<Integer> last = new LinkedList<Integer>(v);

            remove(first, true);
            remove(last, false);

            dfs(first);
            dfs(last);
        }
    }

    boolean ok(LinkedList<Integer> v) {
        if (v.size() == 0)
            return false;
        if (v.size() == 1)
            return true;
        int x = v.get(0), y = v.get(v.size() - 1);
        return y <= 2 * x;
    }

    void remove(LinkedList<Integer> v, boolean first) {
        if (v.size() > 0) {
            if (first) {
                Integer val = v.removeFirst();
                while (v.size() > 0 && v.getFirst().equals(val)) {
                    v.removeFirst();
                }
            } else {
                Integer val = v.removeLast();
                while (v.size() > 0 && v.getLast().equals(val)) {
                    v.removeLast();
                }
            }
        }
    }

    // ----------------------- Library ------------------------
    /**
     * important for speed!!! PrintWriter out=new PrintWriter(new
     * OutputStreamWriter(System.out)); out.print(...); out.close();
     * 
     * @param v
     */
    // leap year is 29
    int[] year = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

    void initSystem() throws IOException {
        if (br != null)
            br.close();
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    void initFile() throws IOException {
        if (br != null)
            br.close();
        br = new BufferedReader(new InputStreamReader(new FileInputStream(
                "input.txt")));
    }

    void printWriter() {
        try {
            PrintWriter pr = new PrintWriter("output.txt");
            pr.println("hello world");
            pr.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    void comparator() {
        Point[] v = new Point[10];
        Arrays.sort(v, new Comparator<Point>() {
            @Override
            public int compare(Point a, Point b) {
                if (a.x != b.x)
                    return -(a.x - b.x);
                return a.y - b.y;
            }
        });
    }

    double distance(Point a, Point b) {
        double dx = a.x - b.x, dy = a.y - b.y;
        return Math.sqrt(dx * dx + dy * dy);
    }

    Scanner in = new Scanner(System.in);

    String ss() {
        return in.next();
    }

    String sline() {
        return in.nextLine();
    }

    int si() {
        return in.nextInt();
    }

    int[] sai(int n) {
        int[] a = new int[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = in.nextInt();
        }
        return a;
    }
    
    int[] si(int n) {
        int[] a = new int[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = in.nextInt();
        }
        return a;
    }

    String[] ss(int n) {
        String[] a = new String[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = ss();
        }
        return a;
    }

    int[] sai_(int n) {
        int[] a = new int[n + 1];
        for (int i = 1; i <= n; i++) {
            a[i] = in.nextInt();
        }
        return a;
    }

    BufferedReader br;
    StringTokenizer tokenizer;
    {
        br = new BufferedReader(new InputStreamReader(System.in));
    }

    void tok() throws IOException {
        tokenizer = new StringTokenizer(br.readLine());
    }

    int toki() throws IOException {

        return Integer.parseInt(tokenizer.nextToken());
    }

    int[] rint(int n) throws IOException {
        int[] a = new int[n];
        for (int i = 0; i < a.length; i++)
            a[i] = Integer.parseInt(tokenizer.nextToken());

        return a;
    }

    int[] rint_(int n) throws IOException {
        int[] a = new int[n + 1];
        for (int i = 1; i <= n; i++)
            a[i] = Integer.parseInt(tokenizer.nextToken());

        return a;
    }

    String[] rstrlines(int n) throws IOException {
        String[] a = new String[n];
        for (int i = 0; i < n; i++) {
            a[i] = br.readLine();
        }
        return a;
    }

    long tokl() {
        return Long.parseLong(tokenizer.nextToken());
    }

    double tokd() {
        return Double.parseDouble(tokenizer.nextToken());
    }

    String toks() {
        return tokenizer.nextToken();
    }

    String rline() throws IOException {
        return br.readLine();
    }

    List<Integer> toList(int[] a) {
        List<Integer> v = new ArrayList<Integer>();
        for (int i : a)
            v.add(i);
        return v;
    }

    static void pai(int[] a) {
        System.out.println(Arrays.toString(a));
    }

    static int toi(Object s) {
        return Integer.parseInt(s.toString());
    }

    static int[] dx3 = { 1, -1, 0, 0, 0, 0 };
    static int[] dy3 = { 0, 0, 1, -1, 0, 0 };
    static int[] dz3 = { 0, 0, 0, 0, 1, -1 };

    static int[] dx = { 1, 0, -1, 1, -1, 1, 0, -1 }, dy = { 1, 1, 1, 0, 0, -1,
            -1, -1 };

    static int INF = 2147483647; // =2^31-1 // -8
    static long LINF = 922337203854775807L; // -8
    static short SINF = 32767; // -32768

    // finds GCD of a and b using Euclidian algorithm
    public int GCD(int a, int b) {
        if (b == 0)
            return a;
        return GCD(b, a % b);
    }

    static List<String> toList(String[] a) {
        return Arrays.asList(a);
    }

    static String[] toArray(List<String> a) {
        String[] o = new String[a.size()];
        a.toArray(o);
        return o;
    }

    static int[] pair(int... a) {
        return a;
    }
}
