Hello!
This is listing of my class

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


public class q1496 {

    /**
     * @param args
     * @throws IOException
     * @throws NumberFormatException
     */
    public static void main(String[] args) throws NumberFormatException, IOException
    {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        int amount = Integer.parseInt(in.readLine());
        String[] source= new String[amount];
        String[] uniT= new String[amount];
        int j=0;
        int count=0;
        for (int i=0;i<amount;i++)
           {
            source[i]=in.readLine();
           }
        Arrays.sort(source);
        uniT[0]=source[0];

        for (int i=0;i<amount;i++)
           {
            if (source[i].equals(uniT[j])!=true)
               {
                j++;
                uniT[j]=source[i];
               }
           }
        for (int i=0;i<=j;i++)
            {
            count=0;
             for (int k=0;k<amount;k++)
                 {
                 if (source[k].equals(uniT[i]))
                     {
                     count++;
                     }
                   }
             if (count>1){System.out.println(uniT[i]);}
            }
    }

}