#include <stdio.h>
#include <malloc.h>
char str[60000];
int str_len = 0;

/// <summary>
/// グローバル変数strの中身を入力された文字列で上書きする
/// </summary>
void ReadString() {
	char c = getchar();
	str_len = 0;

	while (c != '\n') {
		str[str_len] = c;
		c = getchar();
		str_len++;
	}
}

/// <summary>
/// 入力された数字を返す
/// </summary>
/// <returns></returns>
int ReadNum() {
	int negate = 0;
	char c = getchar();
	int num = 0;
	int numCnt = 0;
	while (c != '\n') {
		if (c == '-') {
			negate = 1;
		}
		else {
			num = num * 10 + c - '0';
		}

		c = getchar();
	}
	if (negate == 1) {
		num *= -1;
	}
	return num;
}

/// <summary>
/// 引数*numsのポインタ位置にある配列の中身をstrのスペースで区切られた数字にする
/// 渡されたポインタ位置が、strのスペースの数+1個分　静的にメモリが確保された配列である必要がある
/// </summary>
/// <param name="nums"></param>
/// <returns></returns>
void GetNums(int* nums, int size) {
	for (int i = 0;i < size;i++) {
		nums[i] = 0;
	}
	int numIndex = 0;
	int negate = 0;
	for (int i = 0;i <= str_len;i++) {
		if (str[i] == ' ' || i == str_len) {
			if (negate == 1) {
				nums[numIndex] *= -1;
			}
			negate = 0;
			numIndex++;
			continue;
		}
		if (str[i] == '-') {
			negate = 1;
			continue;
		}
		nums[numIndex] = nums[numIndex] * 10 + (str[i] - '0');
	}
}


int main()
{
	int n = ReadNum();
	int* nums;
	int cnt = 0;
	nums = (int*)malloc(sizeof(int) * (3*n));
	for (int i = 0;i < n;i++) {
		ReadString();
		int work[3];
		GetNums(work,3);
		for (int j = 0;j < 3;j++) {
			nums[i * 3 + j] = work[j];
		}
	}

	for (int i = 0;i < n * 3 - 1;i++) {
		if (nums[i] == -1) continue;
		for (int j = i + 1;j < n * 3;j++) {
			if (nums[j] == -1) continue;
			if (nums[i] == nums[j]) {
				cnt++;
				nums[i] = -1;
				nums[j] = -1;
				break;
			}
		}
	}
	int four = 0;
	
	for (int i = 0;i < n * 3;i++) {
		if (nums[i] != -1) {
			nums[i] = -1;
			four++;
		}
		if (four == 4) {
			four = 0;
			cnt++;
		}
	}
	
	printf("%d\n", cnt);

}