import java.util.Scanner;
public class no29{
    public static void main(String... args){
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int res = 0,tmp;
        int array[] = new int[10];

        for(int i = 0; i < n; i++){
            for(int j = 0; j < 3; j++){
                tmp = scan.nextInt();
                array[tmp-1]++;
                if(array[tmp-1] == 2){
                    array[tmp-1] = 0;
                    res++;
                }
            }
        }

        tmp = 0;
        for(int i = 0; i < 10; i++)
            tmp += array[i];

        while(4 <= tmp){
            tmp -= 4;
            res++;
        }

        System.out.println(res);

    }
}