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.io.*;
import java.util.*;
import java.math.*;
import static java.lang.Math.*;
import static java.lang.Integer.parseInt;
import static java.lang.Long.parseLong;
import static java.lang.Double.parseDouble;
import static java.lang.String.*;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
                                            //(new FileReader("input.in"));
        StringBuilder out = new StringBuilder();
        StringTokenizer tk;
        Reader.init(System.in);
        //PrintWriter pw = new PrintWriter("output.out", "UTF-8");
        
        tk = new StringTokenizer(in.readLine());
        int n = parseInt(tk.nextToken()),s = parseInt(tk.nextToken()),i;
        int [] a = new int[n];
        
        tk = new StringTokenizer(in.readLine());
        for(i=0; i<n; i++)
            a[i] = parseInt(tk.nextToken());
        
        Arrays.sort(a);
        
        int ans = 0;
        for(i=0; i<min(n,s); i++) {
            if(a[i] >= 0) break;
            ans += -a[i];
        }
        
        System.out.println(ans);
    }
}

class Tools {

    public static boolean next_permutation(int[] p, int len) {
        int a = len - 2;
        while (a >= 0 && p[a] >= p[a + 1]) {
            a--;
        }

        if (a == -1) {
            return false;
        }

        int b = len - 1;
        while (p[b] <= p[a]) {
            b--;
        }

        p[a] += p[b];
        p[b] = p[a] - p[b];
        p[a] -= p[b];

        for (int i = a + 1, j = len - 1; i < j; i++, j--) {
            p[i] += p[j];
            p[j] = p[i] - p[j];
            p[i] -= p[j];
        }

        return true;
    }
    
    public static int lower_bound(Comparable[] arr, Comparable key) {
        int len = arr.length;
        int lo = 0;
        int hi = len-1;
        int mid = (lo + hi)/2;
        while (true) {
            int cmp = arr[mid].compareTo(key);
            if (cmp == 0 || cmp > 0) {
                hi = mid-1;
                if (hi < lo)
                    return mid;
            } else {
                lo = mid+1;
                if (hi < lo)
                    return mid<len-1?mid+1:-1;
            }
            mid = (lo + hi)/2;
        }
    }

    public static int upper_bound(Comparable[] arr, Comparable key) {
        int len = arr.length;
        int lo = 0;
        int hi = len-1;
        int mid = (lo + hi)/2;
        while (true) {
            int cmp = arr[mid].compareTo(key);
            if (cmp == 0 || cmp < 0) {
                lo = mid+1;
                if (hi < lo)
                    return mid<len-1?mid+1:-1;
            } else {
                hi = mid-1;
                if (hi < lo)
                    return mid;
            }
            mid = (lo + hi)/2;
        }
    }

}

class Reader {

    static BufferedReader reader;
    static StringTokenizer tokenizer;

    static void init(InputStream input) throws UnsupportedEncodingException {
        reader = new BufferedReader(
                new InputStreamReader(input, "UTF-8"));
        tokenizer = new StringTokenizer("");
    }

    static String next() throws IOException {
        while (!tokenizer.hasMoreTokens()) {
            //TODO add check for eof if necessary
            tokenizer = new StringTokenizer(
                    reader.readLine());
        }
        return tokenizer.nextToken();
    }

    static String nextLine() throws IOException {
        return reader.readLine();
    }

    static int nextInt() throws IOException {
        return Integer.parseInt(next());
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }
}