2591 {
2592 int n;
2593 cin >> n;
2594 int count_123 = 0;
2595 int count_132 = 0;
2596 int count_213 = 0;
2597 int count_231 = 0;
2598 int count_312 = 0;
2599 int count_321 = 0;
2600 for(int i = 0; i < n; i++) {
2601 int a;
2602 int b;
2603 cin >> a >> b;
2604 if(a == 1 && b == 2) {
2605 count_132++;
2606 count_213++;
2607 count_321++;
2608 } else if(a == 1 && b == 3) {
2609 count_123++;
2610 count_231++;
2611 count_312++;
2612 } else if(a == 2 && b == 1) {
2613 count_123++;
2614 count_231++;
2615 count_312++;
2616 } else if(a == 2 && b == 3) {
2617 count_132++;
2618 count_213++;
2619 count_321++;
2620 } else if(a == 3 && b == 1) {
2621 count_132++;
2622 count_213++;
2623 count_321++;
2624 } else if(a == 3 && b == 2) {
2625 count_123++;
2626 count_231++;
2627 count_312++;
2628 }
2629 }
2630 int maximum = count_123;
2631 maximum = max(maximum, count_132);
2632 maximum = max(maximum, count_213);
2633 maximum = max(maximum, count_231);
2634 maximum = max(maximum, count_312);
2635 maximum = max(maximum, count_321);
2636 cout << maximum;
2637 return 0;
2638 }