Problem: You are given array a with n integers and m queries. The i-th query is given with three integers li, ri, xi.

For the i-th query find any position pi (li ≤ pi ≤ ri) so that api ≠ xi.

Input

The first line contains two integers n, m (1 ≤ n, m ≤ 2·105) — the number of elements in a and the number of queries.

The second line contains n integers ai (1 ≤ ai ≤ 106) — the elements of the array a.

Each of the next m lines contains three integers li, ri, xi (1 ≤ li ≤ ri ≤ n, 1 ≤ xi ≤ 106) — the parameters of the i-th query.

Output

Print m lines. On the i-th line print integer pi — the position of any number not equal to xi in segment [li, ri] or the value  - 1 if there is no such number.

Examples

Input

6 4
1 2 1 1 3 5
1 4 1
2 6 2
3 4 1
3 4 2


Output

2
6
-1
4

Solution (in JAVA):

Solution:

import java.io.*;
import java.util.*;
public class CodeForces
{
	
        public static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
	public static void main(String[] args) throws IOException
	{
               
                String s1 = reader.readLine();
                int n = Integer.parseInt(s1.split(" ")[0]);
                int m = Integer.parseInt(s1.split(" ")[1]);
          
                String[] s2 = reader.readLine().split(" ");
                int[] a = new int[n];
  

                for(int i = 1 ; i<n ; i++){
                    a[i] = (s2[i].equals(s2[i-1]))? a[i-1] : i;
                }
                
                int l , r  , index , j;
                String query , x;
                String[] b ;
                StringBuilder output = new StringBuilder();
                for(int i=0 ; i<m ; i++){
                    query = reader.readLine();
                    b = query.split(" ");
                    
                    l = Integer.parseInt(b[0]) ;
                    r = Integer.parseInt(b[1]) ;
                    x = b[2] ;
                    
                    index = (!(s2[r-1].equals(x)))? r :
                            ( a[r-1] < l  ) ? -1 :
                              a[r-1] ;
                    
                    output.append(String.valueOf(index) + "\n");

                }
                System.out.printf("%s",output);
               
        }
}