/* rational numbers in java */
import javax.swing.*;

class rational
{
 
 private int num;
 private int dem;
 private int gcd(int a, int b) 
    {if (a==0) return b; else return gcd(b%a,a);}
  // accessor
 public  int getnum() { return num; }
  // modifier
 public void setnum(int n) { num = n; }

 public int getdem() { return dem; }
  // modifier
 public void setdem(int d) { if (d!=0) dem = d; }

 public rational(int n, int d)  // constructor
    {  int g;
       num = n;  if (d!=0) dem = d; else dem = 1;
       g = gcd(num,dem);
       num = num/g;   dem = dem/g;      
    }  
  
  public void invert() 
    { if (num==0) return;
      int temp;
      temp = num;  num = dem; dem = temp;
    }

  public boolean equals(rational other) // true false
    { return num*other.dem == dem*other.num; }

  public void multx(rational b)
    {
      num = num*b.num;  dem = dem*b.dem;
    }
  public rational mult(rational b)
    { return new rational(num*b.num, dem*b.dem); }
 
  public String toString()  // overriding a superclass method
    { return "" + num + "/" + dem; } 
  // oop style
}  // class rational

public class rats2
{
  public static void main(String[] aaa)
 {
  rational a, b;
  a = new rational(1,2);  b = new rational(2,4);
  System.out.println(a.equals(b));
  a.multx(b);
  b = a.mult(b);
  System.out.println(a);  
  JOptionPane.showMessageDialog(null,b);
  System.exit(0);
 } // main
}// rats2