Pascal :

var
        ycl:array[1..8] of longint=(10,100,1000,10000,100000,1000000,10000000,100000000);
        a:array[0..1000] of longint;
        b:array[0..1000,1..2] of longint;
        n,q,i,j:longint;
procedure qsort(l,r:longint);
var
        i,j,mid,t:longint;
begin
        i:=l;
        j:=r;
        mid:=a[(l+r) div 2];
        repeat
                while a[i]<mid do inc(i);
                while a[j]>mid do dec(j);
                if i<=j then
                begin
                        t:=a[i];
                        a[i]:=a[j];
                        a[j]:=t;
                        inc(i);
                        dec(j);
                end;
        until i>j;
        if i<r then qsort(i,r);
        if l<j then qsort(l,j);
end;
begin
        readln(n,q);
        for i:=1 to n do
                read(a[i]);
        for i:=1 to q do
                read(b[i,1],b[i,2]);
        qsort(1,n);
        for i:=1 to q do
        begin
                j:=1;
                while (a[j] mod ycl[b[i,1]]<>b[i,2]) and (j<=n) do inc(j);
                if j>n then writeln(-1)
                else writeln(a[j]);
        end;
end.

Java :

import java.util.Scanner;

public class Main {
	
	static char a[][] = new char[1001][1001];
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int book[] = new int[1001];
		int len[] = new int[1001];
		int num[] = new int[1001];

		int n = sc.nextInt();
		int q = sc.nextInt();
				
		for(int i=1;i<=n;i++){
			book[i] = sc.nextInt();
		}
		
	    for(int i=1;i<=q;i++) {
	        len[i] = sc.nextInt();
	        num[i] = sc.nextInt();
	        // 10的 len[i]次方
	        int tmp = (int) Math.pow(10,len[i]),min=Integer.MAX_VALUE;
	        for(int j=1;j<=n;j++) {
	        	if(book[j]%tmp==num[i]&&book[j]<min){
	        		min=book[j];
	        	}   	
	        }
	        if(min!=Integer.MAX_VALUE){
	        	System.out.println(min);
	        }else{
	        	System.out.println(-1);
	        }
	    }    
		   
		sc.close();
	}
}