UVA - 272 TEX Quotes

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

public class Main {

    public static void main(String[] args) throws IOException {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        StringBuilder sb = new StringBuilder();
       
        String m = "";
        boolean flag=true;
        while ((m = br.readLine()) != null) {
           
            for(int i=0;i<m.length();i++){
                if(m.charAt(i)=='\"'){
                    if(flag){
                        sb.append("``");
                        flag=false;
                    }else{
                        sb.append("\'\'");
                        flag=true;
                    }
                }else{
                    sb.append(m.charAt(i));
                }
            }
            sb.append("\n");
           
        }
        System.out.print(sb);
    }
}