include <bits/stdc++.h>

using namespace std; int a[100000];

int main() {

int flag = 0, mod = 1, n, k, key, num;
cin >> n >> num;
for (int i = 0; i < n; i++) {
	cin >> a[i];
}
sort(a, a + n);
for (int i = 0; i < num; i++) {
	flag = 0;
	mod = 1;
	cin >> k >> key;
	for (int j = 0; j < k; j++) {
		mod = mod * 10;
	}
	for (int j = 0; j < n; j++) {
		if (a[j] % mod == key) {
			flag = 1;
			cout << a[j] << endl;
			break;
		}
	}
	if (flag == 0) {
		cout << "-1" << endl;
	}
}
return 0;

}