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.File;import java.io.FileInputStream;import java.io.FileNotFoundException;
import java.io.IOException;import java.io.PrintStream;import java.io.PrintWriter;
import java.security.AccessControlException;import java.util.Arrays;import java.util.Collection;
import java.util.Comparator;import java.util.List;import java.util.Map;import java.util.Objects;
import java.util.PriorityQueue;import java.util.Scanner;import java.util.TreeMap;
import java.util.function.Function;import java.util.stream.Collectors;import java.util.stream.IntStream;
import java.util.stream.LongStream;import java.util.stream.Stream;public class _p000034B {
static public void main(final String[] args) throws IOException{p000034B._main(args);}

static private class p000034B extends Solver{public p000034B(){nameIn="in/900/p000034A.in";
singleTest=true;}@Override public void solve()throws IOException{int n=sc.nextInt();
int m=sc.nextInt();if(sc.hasNextLine()){sc.nextLine();}PriorityQueue<Integer>pq=
new PriorityQueue<>();for(int _if0=0;_if0<n;_if0++){int a=sc.nextInt();pq.add(a);
}if(sc.hasNextLine()){sc.nextLine();}int res=0;int count=0;while(!pq.isEmpty()){
int p=pq.poll();if(p>=0){break;}res-=p;count++;if(count==m){break;}}pw.println(res);
}static public void _main(String[]args)throws IOException{new p000034B().run();}}
static private class Pair<K,V>{private K k;private V v;public Pair(final K t,final 
V u){this.k=t;this.v=u;}public K getKey(){return k;}public V getValue(){return v;
}}static private abstract class Solver{protected String nameIn=null;protected String 
nameOut=null;protected boolean singleTest=false;protected boolean preprocessDebug
=false;protected boolean doNotPreprocess=false;protected PrintStream debugPrintStream
=null;protected Scanner sc=null;protected PrintWriter pw=null;final static String 
SPACE=" ";final static String SPACES="\\s+";private void process()throws IOException
{if(!singleTest){int t=lineToIntArray()[0];while(t-->0){solve();}}else{solve();}
}abstract protected void solve()throws IOException;protected String[]lineToArray()
throws IOException{return sc.nextLine().trim().split(SPACES);}protected int[]lineToIntArray()
throws IOException{return Arrays.stream(lineToArray()).mapToInt(Integer::valueOf).toArray();
}protected long[]lineToLongArray()throws IOException{return Arrays.stream(lineToArray()).mapToLong(Long::valueOf).toArray();
}protected void run()throws IOException{boolean done=false;try{if(nameIn!=null && 
new File(nameIn).exists()){try(FileInputStream fis=new FileInputStream(nameIn);PrintWriter 
pw0=select_output();){done=true;sc=new Scanner(fis);pw=pw0;process();}}}catch(IOException 
ex){}catch(AccessControlException ex){}if(!done){try(PrintWriter pw0=select_output();
){sc=new Scanner(System.in);pw=pw0;process();}}}private PrintWriter select_output()
throws FileNotFoundException{if(nameOut!=null){return new PrintWriter(nameOut);}
return new PrintWriter(System.out);}public static Map<Integer,List<Integer>>mapi(final 
int[]a){return IntStream.range(0,a.length).collect(()->new TreeMap<Integer,List<Integer>>(),
(res,i)->{if(!res.containsKey(a[i])){res.put(a[i],Stream.of(i).collect(Collectors.toList()));
}else{res.get(a[i]).add(i);}},Map::putAll);}public static Map<Long,List<Integer>>
mapi(final long[]a){return IntStream.range(0,a.length).collect(()->new TreeMap<Long,
List<Integer>>(),(res,i)->{if(!res.containsKey(a[i])){res.put(a[i],Stream.of(i).collect(Collectors.toList()));
}else{res.get(a[i]).add(i);}},Map::putAll);}public static<T>Map<T,List<Integer>>
mapi(final T[]a){return IntStream.range(0,a.length).collect(()->new TreeMap<T,List<Integer>>(),
(res,i)->{if(!res.containsKey(a[i])){res.put(a[i],Stream.of(i).collect(Collectors.toList()));
}else{res.get(a[i]).add(i);}},Map::putAll);}public static<T>Map<T,List<Integer>>
mapi(final T[]a,Comparator<T>cmp){return IntStream.range(0,a.length).collect(()->
new TreeMap<T,List<Integer>>(cmp),(res,i)->{if(!res.containsKey(a[i])){res.put(a[i],
Stream.of(i).collect(Collectors.toList()));}else{res.get(a[i]).add(i);}},Map::putAll
);}public static Map<Integer,List<Integer>>mapi(final IntStream a){int[]i=new int[]{0};
return a.collect(()->new TreeMap<Integer,List<Integer>>(),(res,v)->{if(!res.containsKey(v))
{res.put(v,Stream.of(i[0]).collect(Collectors.toList()));}else{res.get(v).add(i[0]);
}i[0]++;},Map::putAll);}public static Map<Long,List<Integer>>mapi(final LongStream 
a){int[]i=new int[]{0};return a.collect(()->new TreeMap<Long,List<Integer>>(),(res,
v)->{if(!res.containsKey(v)){res.put(v,Stream.of(i[0]).collect(Collectors.toList()));
}else{res.get(v).add(i[0]);}i[0]++;},Map::putAll);}public static<T>Map<T,List<Integer>>
mapi(final Stream<T>a,Comparator<T>cmp){int[]i=new int[]{0};return a.collect(()->
new TreeMap<T,List<Integer>>(cmp),(res,v)->{if(!res.containsKey(v)){res.put(v,Stream.of(i[0]).collect(Collectors.toList()));
}else{res.get(v).add(i[0]);}},Map::putAll);}public static<T>Map<T,List<Integer>>
mapi(final Stream<T>a){int[]i=new int[]{0};return a.collect(()->new TreeMap<T,List<Integer>>(),
(res,v)->{if(!res.containsKey(v)){res.put(v,Stream.of(i[0]).collect(Collectors.toList()));
}else{res.get(v).add(i[0]);}},Map::putAll);}public static List<int[]>listi(final 
int[]a){return IntStream.range(0,a.length).mapToObj(i->new int[]{a[i],i}).collect(Collectors.toList());
}public static List<long[]>listi(final long[]a){return IntStream.range(0,a.length).mapToObj(i
->new long[]{a[i],i}).collect(Collectors.toList());}public static<T>List<Pair<T,
Integer>>listi(final T[]a){return IntStream.range(0,a.length).mapToObj(i->new Pair<T,
Integer>(a[i],i)).collect(Collectors.toList());}public static List<int[]>listi(final 
IntStream a){int[]i=new int[]{0};return a.mapToObj(v->new int[]{v,i[0]++}).collect(Collectors.toList());
}public static List<long[]>listi(final LongStream a){int[]i=new int[]{0};return 
a.mapToObj(v->new long[]{v,i[0]++}).collect(Collectors.toList());}public static<T>
List<Pair<T,Integer>>listi(final Stream<T>a){int[]i=new int[]{0};return a.map(v->
new Pair<T,Integer>(v,i[0]++)).collect(Collectors.toList());}public static String 
join(final int[]a){return Arrays.stream(a).mapToObj(Integer::toString).collect(Collectors.joining(SPACE));
}public static String join(final long[]a){return Arrays.stream(a).mapToObj(Long::toString).collect(Collectors.joining(SPACE));
}public static<T>String join(final T[]a){return Arrays.stream(a).map(v->Objects.toString(v)).collect(Collectors.joining(SPACE));
}public static<T>String join(final T[]a,final Function<T,String>toString){return 
Arrays.stream(a).map(v->toString.apply(v)).collect(Collectors.joining(SPACE));}public 
static<T>String join(final Collection<T>a){return a.stream().map(v->Objects.toString(v)).collect(Collectors.joining(SPACE));
}public static<T>String join(final Collection<T>a,final Function<T,String>toString)
{return a.stream().map(v->toString.apply(v)).collect(Collectors.joining(SPACE));
}public static<T>String join(final Stream<T>a){return a.map(v->Objects.toString(v)).collect(Collectors.joining(SPACE));
}public static<T>String join(final Stream<T>a,final Function<T,String>toString){
return a.map(v->toString.apply(v)).collect(Collectors.joining(SPACE));}public static
<T>String join(final IntStream a){return a.mapToObj(Integer::toString).collect(Collectors.joining(SPACE));
}public static<T>String join(final LongStream a){return a.mapToObj(Long::toString).collect(Collectors.joining(SPACE));
}public static List<Integer>list(final int[]a){return Arrays.stream(a).mapToObj(Integer::valueOf).collect(Collectors.toList());
}public static List<Integer>list(final IntStream a){return a.mapToObj(Integer::valueOf).collect(Collectors.toList());
}public static List<Long>list(final long[]a){return Arrays.stream(a).mapToObj(Long::valueOf).collect(Collectors.toList());
}public static List<Long>list(final LongStream a){return a.mapToObj(Long::valueOf).collect(Collectors.toList());
}public static<T>List<T>list(final Stream<T>a){return a.collect(Collectors.toList());
}public static<T>List<T>list(final T[]a){return Arrays.stream(a).collect(Collectors.toList());
}}}
