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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.BufferedWriter;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author bibhuty(bibhuty.nit@gmail.com)
 */
public class Main{
	public static void main(String[] args){
		InputStream inputStream=System.in;
		OutputStream outputStream=System.out;
		InputReader in=new InputReader(inputStream);
		OutputWriter out=new OutputWriter(outputStream);
		Task34B_Sale solver=new Task34B_Sale();
		solver.solve(1,in,out);
		out.close();
	}

	static class Task34B_Sale{
		public void solve(int testNumber,InputReader in,OutputWriter out){
			int n=in.nextInt(), m=in.nextInt();
			int cost[]=in.nextIntArray(n);
			Arrays.sort(cost);
			int sum=0;
			for(int i=0;i<m && cost[i]<=0;++i) sum-=cost[i];
			out.print(sum);
		}

	}

	static class InputReader{
		private InputStream stream;
		private byte[] buf=new byte[1024];
		private int curChar;
		private int numChars;
		private InputReader.SpaceCharFilter filter;

		public InputReader(InputStream stream){
			this.stream=stream;
		}

		public int read(){
			if(numChars==-1) throw new InputMismatchException();
			if(curChar>=numChars){
				curChar=0;
				try{
					numChars=stream.read(buf);
				}catch(IOException e){
					throw new InputMismatchException();
				}
				if(numChars<=0) return -1;
			}
			return buf[curChar++];
		}

		public int nextInt(){
			int c=read();
			while(isSpaceChar(c)) c=read();
			int sgn=1;
			if(c=='-'){
				sgn=-1;
				c=read();
			}
			int res=0;
			do{
				if(c<'0' || c>'9')
					throw new InputMismatchException();
				res*=10;
				res+=c-'0';
				c=read();
			}while(!isSpaceChar(c));
			return res*sgn;
		}

		public boolean isSpaceChar(int c){
			if(filter!=null)
				return filter.isSpaceChar(c);
			return c==' ' || c=='\n' || c=='\r' || c=='\t' || c==-1;
		}

		public int[] nextIntArray(int size){
			int[] array=new int[size];
			for(int i=0;i<size;i++)
				array[i]=nextInt();
			return array;
		}

		public interface SpaceCharFilter{
			boolean isSpaceChar(int ch);

		}

	}

	static class OutputWriter{
		private final PrintWriter writer;

		public OutputWriter(OutputStream outputStream){
			writer=new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
		}

		public OutputWriter(Writer writer){
			this.writer=new PrintWriter(writer);
		}

		public void print(Object... objects){
			for(int i=0;i<objects.length;i++){
				if(i!=0){
					writer.print(' ');
				}
				writer.print(objects[i]);
			}
		}

		public void close(){
			writer.close();
		}

	}
}

