AABBAAC

3.6

17 votes
Problem

You are given an array S of N strings numbered from 0 to N-1. You build string sequence Ti by the following rules:

  1. T0 = S0
  2. Ti = Ti-1 + reverse(Ti-1) + Si

Now please answer M queries: by non-negative integer x output x-th character of the TN-1 in 0-based indexation. It's guaranteed that x-th character of the TN-1 exists.

Input
The first line contains T - the number of test cases. Then T test cases follow.
Each test case starts with line containing 2 integers: N and M. Next N lines describe array S - one string per line. Then M lines follow describing queries - one non-negative integer per line.

Output
Output T lines. Each line should contain one string containing answers for the corresponding test case. Don't separate answers which belong to one test case by whitespaces or anything else.

Constraints

  • T100
  • length of each Si100
  • N50
  • M1000
  • N5 in 40% of the test data
Time Limit: 2
Memory Limit: 256
Source Limit:
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