import java.util.Random;

public class GCDTest {

  public static Random rand = new Random();

  /**
   * requires: - 'a' >= 0 and 'b' >= 0
   * ensures:  - the result 'r' divides 'a' and 'b', i.e. a % r == 0 and
   *             b % r  == 0
   *           - There exists no 'v' > 'r' such that 'v' divides 'a' and 'b'.
   **/
  public static int euclid(int a, int b) {
    if (b == 0)
      return a;
    return euclid(b, a % b);
  }

  /**
   * requires: - 'a' > 0 and 'b' > 0
   * ensures:  - the result 'r' divides 'a' and 'b', i.e. a % r == 0 and
   *             b % r  == 0
   *           - There exists no 'v' > 'r' such that 'v' divides 'a' and 'b'.
   **/
  public static int binary(int a, int b) {
    int d = 0;
    while (a % 2 == 0 || b % 2 == 0) {
      a = a / 2;
      b = b / 2;
      d++;
    }
    while (a != b) {
      if (a % 2 == 0) {
        a = a / 2;
      } else if (b % 2 == 0) {
        b = b / 2;
      } else if (a > b) {
        a = (a - b) / 2;
      } else {
        b = (b - a) / 2;
      }
    }
    while (d != 0) {
      a = a * 2;
      d = d - 1;
    }
    return a;
  }

  public static int randomValue() {
    // TODO 
    return 0;
  }

  public static boolean test(int a, int b) {
    try {
      // TODO
      return false;
    } catch (Exception e) {
      e.printStackTrace();
      return false;
    }
  }

  public static void main(String[] arg) {
    for (int i = 0; i < 10000; i++) {
      int a = randomValue();
      int b = randomValue();
      if (!test(a, b)) {
        System.out.println("a: " + a);
        System.out.println("b: " + b);
        System.exit(0);
      }
    }
    System.out.println("Done.");
  }

}