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



public class ba9n {

    public static void array(String[] shop){
        for(int x=0;x < shop.length;x++){
            System.out.println(shop[x]);
        }
    }

    public static void arrayscanner(String[] shop) throws IOException{
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        for(int x = 0;x < shop.length;x++){
            shop[x] = in.readLine();
        }
    }

    public static void task(String[] shop){
        int answer = 0;
        for(int x = 0,y = 0;x < shop.length;x++){
            if(shop[x] == "-1"){
                continue;
            }
            for(;y < shop.length;y++){

                if (x == y){
                    continue;
                }
                if (shop[x].equals(shop[y]) == true){
                    answer++;
                    shop[y] = "-1";
                }
            }
            y = 0;
        }
        System.out.println(answer);
    }

    public static void main(String[] args) throws IOException {
        Scanner in = new Scanner(System.in);

        int allshops = in.nextInt();
        String[] shop = new String[allshops];

        arrayscanner(shop);
        //array(shop);
        task(shop);
    }

}

In my compiller all worked good!