include <stdio.h>

void Sort_PO(int arr[],int n);
//n为所查找ID的位数 m为ID 数组arr为编码库 s为编码总数量
int last_ret(int arr[],int n,int m,int s);
int POW_10(int n);
int main()
{
int n = 0, q = 0;//藏书数量和读者数量
int i = 0;
int ID_book[1000],ID_demand_len[1000],ID_demand[1000];
//数据输入
scanf("%d %d",&n,&q);
for(i = 0; i<n; i++)
scanf("%d",&ID_book[i]);
for(i = 0; i<q; i++)
scanf("%d %d",&ID_demand_len[i],&ID_demand[i]);
//调用函数
Sort_PO(ID_book,n);//将图书编码按从小到大排序
//输出结果
for(i = 0; i<q; i++)
{
int ret = last_ret(ID_book,ID_demand_len[i],ID_demand[i],n);
printf("%d\n",ret);
}
return 0;
}
void Sort_PO(int arr[],int n)//利用冒泡排序实现数组正序排列
{
int i, j;
int flag = 1;
for(i = 0; i<n-1; i++)
{
for(j = 0; j<n-i-1; j++)
{
if(arr[j+1]<arr[j])
{
int tmp = arr[j+1];
arr[j+1] = arr[j];
arr[j] = tmp;
flag = 0;
}
}
if(flag)
break;
}
}
int last_ret(int arr[],int n,int m,int s)
{
int i = 0, j = 0;
int tmp;
int sum = 0;
for(i = 0; i<s; i++)//从小到大遍历编码
{
tmp = arr[i];
sum = 0;
for( j = 0; j<n; j++)
{
sum += (tmp%10)*POW_10(j);
tmp /= 10;
}
if(m == sum)
{
return arr[i];
}
}
return -1;
}
int POW_10(int n)
{
int i = 0;
int mult = 1;
for(i = 0; i<n; i++)
mult *= 10;
return mult;
}