import java.util.Scanner;
public class IncomeStatistics {
  final static int LOW_END = 10; // low end of incomes
  final static int HIGH_END = 100; // high end of incomes
  final static int TABLE_SIZE = HIGH_END - LOW_END + 1;

  int[] incomeData; // used to store the income data,
  // incomeData[G] stores the total number of
  // people that fall into the G-thousand-dollar group

  public IncomeStatistics() {
    incomeData = new int[TABLE_SIZE];
  } // end constructor

  public void readData() {
  // -----------------------------------------------------
  // Reads and organizes income statistics.
  // Precondition: The calling code gives directions and
  // prompts the user. Input data is error-free, and each
  // input line is in the form G N, where N is the number of
  // people with an income in the G-thousand-dollar group
  // and LOW_END <= G <= HIGH_END. An input line with values
  // of zero for both G and N terminates the input.
  // Postcondition: incomeData[G-LOW_END] = total number of
  // people with an income in the G-thousand-dollar group
  // for each G read. The values read are displayed.
  // -------------------------------------------------------
    int group, number; // input values
    Scanner input = new Scanner(System.in);

    for (group = LOW_END; group <= HIGH_END; ++group) {
      // clear array
      incomeData[index(group)] = 0;
    } // end for

    group = input.nextInt();
    number = input.nextInt();
    while ((group != 0) || (number != 0)) {
      System.out.println("Income group "+group+" contains " +
                         number + " people.");
      incomeData[index(group)] += number;
      group = input.nextInt();
      number = input.nextInt();
    } // end while
  } // end readData

  private int index(int group) {
  // Returns the array index corresponding to group number.
    return group - LOW_END;
  } // end index

  // other methods for class IncomeStatistics would follow

} // end IncomeStatistics