#include<stdio.h>

int main(void){

	int n;
	int count[10] = {0};
	int power = 0;
	int flag = 0;

	scanf("%d",&n);

	int temp;
	for(int i = 0;i < n;i++){
		for(int j = 0;j < 3;j++){
			scanf("%d",&temp);
			count[temp-1]++;
		}
	}

	for(;;){
		for(int i = 0;i < 10;i++){
			if(count[i] >= 2){
				power++;
				count[i] -= 2;
				flag++;
			}
		}

		if(flag == 0) break;
		flag = 0;
	}

	for(;;){
		for(int i = 0;i < 10;i++){
			if(count[i] >= 1){
				if(flag == 4) break;
				flag++;
				count[i]--;
			}
		}

		if(flag == 4) power++;
		if(flag == 0) break;

		flag = 0;
	}

	printf("%d\n",power);

	return 0;
}