22

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

typedef pair<int, int> PII; // 使用 PII 表示一个包含两个整数的 pair

const int N = 100010;

int n, m, T;
int priority[N], lastOrder[N];
bool inCache[N];
PII orders[N];

int main()
{
scanf("%d%d%d", &n, &m, &T); // 输入外卖店数量n、订单数量m、和时刻T

for (int i = 0; i < m; i++)
    scanf("%d%d", &orders[i].first, &orders[i].second);  // 输入每个订单的时刻和外卖店编号

sort(orders, orders + m);  // 按照时刻对订单进行排序

for (int i = 0; i < m;)
{
    int j = i;
    while (j < m && orders[j] == orders[i])
        j++;
    int time = orders[i].first, id = orders[i].second, count = j - i;
    i = j;

    // 处理 t 时刻之前的信息
    priority[id] -= time - lastOrder[id] - 1;
    if (priority[id] < 0)
        priority[id] = 0;
    if (priority[id] <= 3)
        inCache[id] = false;

    // 处理 t 时刻的信息
    priority[id] += count * 2;
    if (priority[id] > 5)
        inCache[id] = true;

    lastOrder[id] = time;
}

for (int i = 1; i <= n; i++)
    if (lastOrder[i] < T)
    {
        priority[i] -= T - lastOrder[i];
        if (priority[i] <= 3)
            inCache[i] = false;
    }

int result = 0;
for (int i = 1; i <= n; i++)
    result += inCache[i];

printf("%d\n", result);  // 输出结果

return 0;

}