UVA - 10921 - Find the Telephone

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;

public class Main {

    public static void main(String[] args) throws IOException {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        StringBuffer sb = new StringBuffer("");
        String m="";
        StringBuilder temp=new StringBuilder("");
        while (true) {
            int car = br.read();
            if (car < 0)
                 break;                   
            char c=(char) car;           
               sb.append(strM(c));
            }
        System.out.print(sb);
    }
    static char strM(char x){
        if(x=='A' || x=='B' ||x=='C' )
            return '2';
        if(x=='D' || x=='E' ||x=='F' )
            return '3';
        if(x=='G' || x=='H' ||x=='I' )
            return '4';
        if(x=='J' || x=='K' ||x=='L' )
            return '5';
        if(x=='M' || x=='N' ||x=='O' )
            return '6';
        if(x=='P' || x=='Q' ||x=='R' ||x=='S')
            return '7';
        if( x=='T' ||x=='U' || x=='V')
            return '8';
        if(x=='W' || x=='X' ||x=='Y' ||x=='Z')
            return '9';
        return x;
    }
}