import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Stack;

public class unique {
    public static void main(String[] args) throws IOException {

        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        Map<Integer,Integer> map = new HashMap<Integer,Integer>();
        int[] me = new int[1000001];
        int[] mi = new int[1000001];
	    
	    int n,m;
	    while(true) {
		    String line = reader.readLine();
                    while(line.trim().equals("")) line = reader.readLine();
		    String[] arr = line.trim().split(" ");
                    m = Integer.parseInt(arr[0]);
                    n= Integer.parseInt(arr[1]);
                    
                    if(m == 0 && n == 0) return;
                    
                    for(int i = 1; i<=m;i++) {
                        line = reader.readLine();
                        me[i] = Integer.parseInt(line.trim());
                    }
                    
                    map.clear();
                    mi[0] = 1;
                    int bg = 1;
                    for(int i=1;i<=m;i++) {
                        //System.out.println(map.toString());
                        if(map.containsKey(me[i])) {
                            int ilast = map.get(me[i]);
                            mi[i] = 1 + ilast;
//                            for(int j = ilast;j>=bg;j--) {
//                                map.remove(me[i]);
//                            }
                            bg = ilast + 1;
                        }
                        else {
                            mi[i] = mi[i-1];
                        }
                        map.put(me[i], i);
                    }
                    
                    
                    for(int i = 0; i < n;i++) {
                        line = reader.readLine();
                        arr = line.trim().split(" ");
                        int z = Integer.parseInt(arr[0].trim());
                        int k = Integer.parseInt(arr[1].trim());
                        
                        if(mi[k] <= z) {
                            System.out.println("OK");
                        } else {
                            System.out.println(""+me[mi[k]-1]);
                        }
                    }
                    System.out.println();
	    }
        
    }
    
    
}