import gov.lanl.java.UserInput;
// birth rate of 'roos = 1/2
// death rate of 'roos = 1/18
// initial population of 'roos = 50

public class Roo {
  public static void main(String args[]) {
      double birthRate = 1.0/2; // Why "1.0"? Why not just "1"?
      double deathRate = 1.0/3;
      int initialRoos = 50;
      int oldRoos, newRoos;

      System.out.println("0  " + initialRoos);

      oldRoos = initialRoos;

      for(int i = 1; i <= 10; i++) {
        newRoos = (int) (oldRoos + birthRate*oldRoos - deathRate*oldRoos);
        // What does the "(int)" do above? Why do we do it?
        System.out.println(i + "  " + newRoos);
        oldRoos = newRoos;
      }
  }
}