#include<bits/stdc++.h>

	#include<iostream>
  
	using namespace std;
  
	int main(){
  
	//	freopen(".in","r",stdin);
  
	//	freopen(".out","w",stdout);
  
		int n,q,a[1005],b[1005],c[1005];
  
		cin>>n>>q;
  
		for(int i=1;i<=n;i++){
                          
			cin>>a[i];
  
		}
  
		sort(a+1,a+1+n);
  
		for(int i=1;i<=q;i++){
                          
			cin>>b[i]>>c[i];
  
		}
  
		for(int i=1;i<=q;i++){
                          
			bool g=0;
                          
			for(int j=1;j<=n;j++){
  
				if(c[i]==a[j]%(int)pow(10,b[i])){
  
					cout<<a[j]<<endl;
  
					g=1;
  
					break;
  
				}
  
			}
  
			if(g==0){
  
				cout<<-1<<endl;
  
			}
  
		}
  
		return 0;
  
}