variable sized array
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
//using namespace std;
int main() {
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
int n; //number of Arrays
int q; //number of Queries
int tempValue; //would be used to store the input value of each element in inner vector
//storing the number of arrays in 'n' and number of queries in 'q'
std::cin >> n >> q;
////////////////////////
/*creation of vectors*/
//////////////////////
//creating 'n' number of vector<int>
std::vector<std::vector<int>> a(n);
int numberOfElements; //number of elements in each inner vector
//for each vector
for(int i = 0; i < n; i++){
//store the number of elements desired
std::cin >> numberOfElements;
//runs 'numberOfElements times
for(int j = 0; j < numberOfElements; j++){
std::cin >> tempValue;
a[i].push_back(tempValue);
}
}
///////////////////////
/*queries of vectors*/
/////////////////////
int outVector; //stores the queried outer vector index
int inVector; //stores the queried inner vector index
//runs 'q' times
for(int i = 0; i < q; i++){
std::cin >> outVector >> inVector;
std::cout << a[outVector][inVector];
std::cout << std::endl;
}
return 0;
}