Consider an n element array, a, where each index i in the array contains a reference to an array of ki integers (where the value of ki varies from array to array). See the Explanation section below for a diagram.
Given a , you must answer q queries. Each query is in the format i j, where denotes an index in array a and j denotes an index in the array located at a[i] . For each query, find and print the value of element j in the array at location a[i] on a new line.
The first line contains two space-separated integers denoting the respective values of n (the number of variable-length arrays) and q (the number of queries).
Each line i of the n subsequent lines contains a space-separated sequence in the format k a[i]0 a[i]1 … a[i]k-1 describing the K-element array located at a[i].
Each of the q subsequent lines contains two space-separated integers describing the respective values of i (an index in array ) and j (an index in the array referenced by a[i] ) for a query.
- All indices in this challenge are zero-based.
- All the given numbers are non negative and are not greater than 106.
For each pair of i and j values (i.e., for each query), print a single integer that denotes the element located at index j of the array referenced by a[i]. There should be a total of q lines of output.
3 1 5 4
5 1 2 8 9 3
The diagram below depicts our assembled Sample Input:
We perform the following q=2 queries:
Find the array located at index i=0 , which corresponds to a=[1,5,4] . We must print the value at index j=1 of this array which, as you can see, is 5 .
Find the array located at index i=1 , which corresponds to a=[1,2,8,9,3] . We must print the value at index j=3 of this array which, as you can see, is 9 .