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.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.StringTokenizer;


public class Notequalonasegment {

	public static void main(String[] args) {
		
		
		MyScannerneos sc=new MyScannerneos();
		PrintWriter out=new PrintWriter(System.out);
		int n=sc.nextInt();
		int m=sc.nextInt();
		int a[]=new int[n+1];
		int z[]=new int[n+1];
		z[1]=-1;
		for(int i=1;i<=n;i++)
		{
			a[i]=sc.nextInt();
			if(i!=1)
			{
				if(a[i]!=a[i-1])
				z[i]=i-1;
				else
					z[i]=z[i-1];
			}
			
		}
		for(int i=1;i<=m;i++)
		{
			int l=sc.nextInt();
			int r=sc.nextInt();
			int x=sc.nextInt();
			if(x!=a[r])
				out.println(r);
			else{
				if(z[r]>=l)
				out.println(z[r]);
				else
					out.println(-1);
			}
		}
		out.close();

	}

}
class MyScannerneos
{
	BufferedReader br;
	StringTokenizer st;
	MyScannerneos()
	{
		br=new BufferedReader(new InputStreamReader(System.in));
	}
	String next()
	{
		
		while(st==null || !st.hasMoreTokens())
		{
			try
			{
				st=new StringTokenizer(br.readLine());
			}
			catch(Exception e)
			{
				e.printStackTrace();
			}
		}
		return st.nextToken();
		
	}
	int nextInt()
	{
		return Integer.parseInt(next());
	}
	long nextLong()
	{
		return Long.parseLong(next());
	}
	double nextDouble()
	{
		return Double.parseDouble(next());
	}
	String nextLine()
	{
		String str="";
		try
		{
			str=br.readLine();
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		return str;
		
	}
}