import java.util.Arrays;
import java.util.Comparator;
import java.util.Scanner;

public class NestedBox {

    private static int n;

    private static long[][] boxes;

    private static boolean[] checked;

    private static int max;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        n = Integer.parseInt(sc.next());
        boxes = new long[n][3];
        checked = new boolean[n];
        for (int i = 0; i < n; i++) {
            boxes[i][0] = Long.parseLong(sc.next());
            boxes[i][1] = Long.parseLong(sc.next());
            boxes[i][2] = Long.parseLong(sc.next());
            Arrays.sort(boxes[i]);
        }
        sc.close();
        Arrays.sort(boxes, new Comparator<long[]>() {
            @Override
            public int compare(long[] o1, long[] o2) {
                if (o1[0] < o2[0]) {
                    return -1;
                } else if (o1[0] > o2[0]) {
                    return 1;
                }
                if (o1[1] < o2[1]) {
                    return -1;
                } else if (o1[1] > o2[1]) {
                    return 1;
                }
                if (o1[2] < o2[2]) {
                    return -1;
                } else if (o1[2] > o2[2]) {
                    return 1;
                }
                return 0;
            }
        });
        max = 1;
        nest(0, 1);
        System.out.println(max);
    }

    private static void nest(int index, int count) {
        if (checked[index]) {
            return;
        }
        for (int i = index + 1; i < n; i++) {
            if (isIn(index, i)) {
                nest(i, count + 1);
            }
        }
        if (count > max) {
            max = count;
        }
        checked[index] = true;
    }

    private static boolean isIn(int innerIndex, int outerIndex) {
        long[] inner = boxes[innerIndex];
        long[] outer = boxes[outerIndex];
        return inner[0] < outer[0] && inner[1] < outer[1] && inner[2] < outer[2];
    }

}