// https://www.hackerrank.com/challenges/java-arraylist/problem import helper.InputHelper; public class JavaArraylist { public static void main(String[] args) { int length = InputHelper.takeLength(); int[][] matrix = new int[length][]; for (int row = 0 ; row < length ; row++) { int columns = InputHelper.takeLength(); matrix[row] = new int[columns]; matrix[row] = InputHelper.get1DArray(columns); } int queries = InputHelper.takeLength(); while (queries-- > 0) { int row = InputHelper.takeLength(); int column = InputHelper.takeLength(); System.out.println( row - 1 < length && column - 1 < matrix[row - 1].length ? matrix[row - 1][column - 1] : "ERROR!" ); } } }