#include <iostream>
#include <algorithm>
#include <cmath>
using namespace std;
const int N = 1e5 + 10;
struct lulu
{
  int time1 = 0;
  int time2 = 0;
  int lev;
} sal[N]; 
struct dudu
{
  int t;
  int id;
} putin[N]; 
bool cmp(struct dudu a, struct dudu b)
{
  return a.t < b.t;
} 
int ans[N];
int res = 0;
int main()
{
  int n, m, T;
  cin >> n >> m >> T;
  for (int i = 1; i <= m; i++)
    cin >> putin[i].t >> putin[i].id;
  sort(putin + 1, putin + m + 1, cmp);
  for (int i = 1; i <= m; i++) 
  {
    sal[putin[i].id].time2 = putin[i].t;
    if (sal[putin[i].id].time1 == 0 || sal[putin[i].id].time2 - sal[putin[i].id].time1 <= 1)
      goto end;
    int chuchu;
    chuchu = abs(sal[putin[i].id].time2 - sal[putin[i].id].time1 - 1);
    if (sal[putin[i].id].lev > chuchu)
      sal[putin[i].id].lev -= chuchu;
    else
      sal[putin[i].id].lev = 0; 
    sal[putin[i].id].time1 = sal[putin[i].id].time2;
    if (sal[putin[i].id].lev > 5)
      ans[putin[i].id] = 1;
    else if (sal[putin[i].id].lev <= 3)
      ans[putin[i].id] = 0;
  end:
  {
    sal[putin[i].id].lev += 2;
    sal[putin[i].id].time1 = sal[putin[i].id].time2;
    if (sal[putin[i].id].lev > 5)
      ans[putin[i].id] = 1;
    else if (sal[putin[i].id].lev <= 3)
      ans[putin[i].id] = 0;
  }
  }
  for (int i = 1; i <= n; i++)
  {
    int tmp = T - sal[i].time1;
    sal[i].lev -= tmp;
    if (sal[i].lev <= 3)
      ans[i] = 0;
    if (ans[i] == 1)
      res++;
  }
  cout << res << endl;
  return 0;
}