import javax.swing.*;

class Vignere
{
    public static void main(String[] args)
    {
        
        String message, key;
        StringBuffer encodedMessage, decodedMessage; 

        message = JOptionPane.showInputDialog(null,"Enter the Message");
        key = JOptionPane.showInputDialog(null,"Enter the key");
        
        encodedMessage = new StringBuffer();
        decodedMessage = new StringBuffer();
        
        int messageLength = message.length();
        int keylength = key.length();
        int i,j,code;
        char ch;
        
        for (i=0;i<messageLength;i++) {
           j = i%keylength;
           code = (int) message.charAt(i) + (int) key.charAt(j)-65;
           encodedMessage.append((char) code);
           }
           
       JOptionPane.showMessageDialog(null, "The coded message is " + encodedMessage);
       
       for (i=0;i<messageLength;i++) {
           j = i%keylength;
           code = (int) encodedMessage.charAt(i) - (int) key.charAt(j)+65;
           decodedMessage.append((char) code);
           }
       JOptionPane.showMessageDialog(null, "The decoded message is " + decodedMessage);
       System.exit(0);
    }
}