Emily's birthday is next week and Jack has decided to buy a present for her. He knows she loves books so he goes to the local bookshop, where there are n books on sale from one of m genres.

In the bookshop, Jack decides to buy two books of different genres.

Based on the genre of books on sale in the shop, find the number of options available to Jack for choosing two books of different genres for Emily. Options are considered different if they differ in at least one book.

The books are given by indices of their genres. The genres are numbered from 1 to m.

Input

The first line contains two positive integers n and m (2 ≤ n ≤ 2·105, 2 ≤ m ≤ 10) — the number of books in the bookstore and the number of genres.

The second line contains a sequence a1, a2, ..., an, where ai (1 ≤ ai ≤ m) equals the genre of the i-th book.

It is guaranteed that for each genre there is at least one book of that genre.

Output

Print the only integer — the number of ways in which Jack can choose books.

It is guaranteed that the answer doesn't exceed the value 2·109.

Examples

Input

4 3
2 1 3 1


Output

5


Input

7 4
4 2 3 1 2 4 3


Output

18

Note

The answer to the first test sample equals 5 as Sasha can choose:

  1. the first and second books, 
  2. the first and third books, 
  3. the first and fourth books, 
  4. the second and third books, 
  5. the third and fourth books. 
100 10
7 4 5 5 10 10 5 8 5 7 4 5 4 6 8 8 2 6 3 3 10 7 10 8 6 2 7 3 9 7 7 2 4 5 2 4 9 5 10 1 10 5 10 4 1 3 4 2 6 9 9 9 10 6 2 5 6 1 8 10 4 10 3 4 10 5 5 4 10 4 5 3 7 10 2 7 3 6 9 6 1 6 5 5 4 6 6 4 4 1 5 1 6 6 6 8 8 6 2 6
 3 2
1 2 2
 12 3
1 2 3 1 2 3 1 2 3 1 2 3
 100 3
2 1 1 1 3 2 3 3 2 3 3 1 3 3 1 3 3 1 1 1 2 3 1 2 3 1 2 3 3 1 3 1 1 2 3 2 3 3 2 3 3 1 2 2 1 2 3 2 3 2 2 1 1 3 1 3 2 1 3 1 3 1 3 1 1 3 3 3 2 3 2 2 2 2 1 3 3 3 1 2 1 2 3 2 1 3 1 3 2 1 3 1 2 1 2 3 1 3 2 3
 100 5
5 5 2 4 5 4 4 4 4 2 5 3 4 2 4 4 1 1 5 3 2 2 1 3 3 2 5 3 4 5 1 3 5 4 4 4 3 1 4 4 3 4 5 2 5 4 2 1 2 2 3 5 5 5 1 4 5 3 1 4 2 2 5 1 5 3 4 1 5 1 2 2 3 5 1 3 2 4 2 4 2 2 4 1 3 5 2 2 2 3 3 4 3 2 2 5 5 4 2 5
 9 2
1 1 1 1 2 1 1 1 1
 10 10
1 2 3 4 5 6 7 8 9 10
 2 2
1 2

4428
 2
 48
 3296
 3953
 8
 45
 1

import java.util.*;
import java.io.*;
public class b609
{
    
    /************************ SOLUTION STARTS HERE ************************/
    
    //DONT FORGET TO COMMIT AND PUSH TO GITHUB
    
    private static void solve(FastScanner s1, FastWriter out){
    	int n=s1.nextInt();
    	int m=s1.nextInt();
    	if(n==m){
    		int ct=0;
    		for(int i=n-1;i>=0;i--)ct+=i;
    		out.println(ct);
    		return;
    	}
    	int arr[]=new int[m+1];
    	for(int i=0;i<n;i++){
    		arr[s1.nextInt()]++;
    	}
    	Arrays.sort(arr);
    	int ct=(n*(n-1))/2;
    	for(int j=1;j<=m;j++){
    		ct-=((arr[j]*(arr[j]-1))/2);
    	}
    	out.println(ct);
    	
    	
    	
	

    }

    /************************ SOLUTION ENDS HERE ************************/
    
    
    
    /************************ TEMPLATE STARTS HERE ************************/
    
    public static void main(String []args) throws IOException {
	FastScanner in  = new FastScanner(System.in);
	FastWriter  out = new FastWriter(System.out);
	solve(in, out);
	in.close();
	out.close();
    }    
    
    static class FastScanner{
	public BufferedReader reader;
	public StringTokenizer st;
	public FastScanner(InputStream stream){
	    reader = new BufferedReader(new InputStreamReader(stream));
	    st = null;
	}
	public String next(){
	    while(st == null || !st.hasMoreTokens()){
		try{
		    String line = reader.readLine();
		    if(line == null) return null;
		    st = new StringTokenizer(line);
		}catch (Exception e){
		    throw (new RuntimeException());
		}
	    }
	    return st.nextToken();
	}
	public String nextLine(){
            String str = null;
            try {
                str = reader.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
	public int nextInt(){
	    return Integer.parseInt(next());
	}
	public long nextLong(){
	    return Long.parseLong(next());
	}
	public double nextDouble(){
	    return Double.parseDouble(next());
	}
	int[] nextIntArray(int n) {
	    int[] arr = new int[n];
	    for (int i = 0; i < n; i++) {
		arr[i] = nextInt();
	    }
	    return arr;
	}

	long[] nextLongArray(int n) {
	    long[] arr = new long[n];
	    for (int i = 0; i < n; i++) {
		arr[i] = nextLong();
	    }
	    return arr;
	}
	public void close(){	
	    try{ reader.close(); } catch(IOException e){e.printStackTrace();}
	}
    }
    static class FastWriter{
	BufferedWriter writer;
	public FastWriter(OutputStream stream){
	    writer = new BufferedWriter(new OutputStreamWriter(stream));
	}
	public void print(int i) {
	    print(Integer.toString(i));
	}
	public void println(int i) {
	    print(Integer.toString(i));
	    print('\n');
	}
	public void print(long i) {
	    print(Long.toString(i));
	}
	public void println(long i) {
	    print(Long.toString(i));
	    print('\n');
	}
	public void print(double i) {
	    print(Double.toString(i));
	}
	public void print(boolean i) {
	    print(Boolean.toString(i));
	}
	public void print(char i) {
	    try{writer.write(i);} catch(IOException e){e.printStackTrace();}
	}
	public void print(String s){
	    try{writer.write(s);} catch(IOException e){e.printStackTrace();}
	}
	public void println(String s){
	    try{writer.write(s);writer.write('\n');} catch(IOException e){e.printStackTrace();}
	}
	public void println(){
	    try{writer.write('\n');} catch(IOException e){e.printStackTrace();}
	}
	public void print(int arr[])
	{
	    for (int i = 0; i < arr.length; i++) {
		print(arr[i]);
		print(' ');
	    }
	}
	public void close(){
	    try{writer.close();} catch(IOException e){e.printStackTrace();}
	}
    }
    
    /************************ TEMPLATE ENDS HERE ************************/
}
