import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class OperationButton extends Button
{
  String 運算符號;
  public OperationButton(String s)
   {
    super(s);
    運算符號=s;
    setForeground(Color.red);
   }
  public String get運算符號()
   {
     return 運算符號;
   }
}