#include<bits/stdc++.h>
using namespace std;
int n,q,a[1001],c;
long long int d=1;
struct reader{
	long long int x;
	int y;//x:长度 y:需求码 
}b[1001];
int main(){
	//freopen("librarian.in","r",stdin);
	//freopen("librarian.out","w",stdout);
	scanf("%d%d",&n,&q);
	for(int i=0;i<n;i++){
		scanf("%d",&a[i]);
	}
	for(int i=0;i<q;i++){
		scanf("%d%d",&c,&b[i].y);
		d=1;
		for(int i=0;i<c;i++){
			d*=10;
		}
		b[i].x=d;
	}
	for(int i=0;i<q;i++){
		int minn=-1;
		for(int j=0;j<n;j++){
			if(a[j]%b[i].x==b[i].y){
				if(minn=-1||a[j]<minn)minn=a[j];
			}
		}
		printf("%d\n",minn);
	}
}