#include<bits/stdc++.h>
using namespace std;
int n, q, minn = 10000000, a[1010];
int  book[1010], need[1010];
bool x=0;
int jisuanweishu(int a, int b) {
	int s = 1, d = 0;
	for (int m = 1; m <= n; m++) {


		for (int i = 1; i <= a; i++) {
			d = book[m] / s % 10 + d;
			s = s * 10;
		}
		if (d == b) {
			minn = min(minn, book[m]) ;
			 x=1;
		}
	}
	if (x==1) {
		return minn;
	} else {
		return -1;
	}

}
int main() {
	cin >> n >> q;
	for (int i = 1; i <= n; i++) {
		cin >> book[i];
	}
	for (int i = 1; i <= q; i++) {
		cin >> a[i] >> need[i];
	}
	for (int i = 1; i <= n; i++) {
		cout << jisuanweishu(a[i], need[i]) << endl;
	}
	return 0;
}

测试点 怎么做啊；