#include <bits/stdc++.h>
#define x first
#define y second
using namespace std;
typedef pair<int,int> PII;
int n,m,T;
const int maxn=1e5+10;
PII order[maxn];
int score[maxn],last[maxn];
bool st[maxn];
int main(){
    scanf("%d%d%d", &n, &m, &T);
    for (int i = 0; i < m; i ++ ) scanf("%d%d", &order[i].x, &order[i].y);
    sort(order, order + m);

    for(int i=0; i<m; ){
        int j=i;
        while(j<m&&order[i]==order[j])j++;
        int t=order[i].x,id=order[i].y;
        int cnt=j-i;
        i=j;

        score[id]-=t-last[id]-1;////
        if(score[id]<=0)score[id]=0;
        if(score[id]<=3)st[id]=false;

        score[id]+=2*cnt;
        last[id]=t;
        if(score[id]>5)st[id]=true;
    }
    for(int i=1; i<=n; i++){
        if(last[i]<T){
            score[i]-=T-last[i];///
            if(score[i]<=3)st[i]=false;
        }
    }
    int res=0;
    for(int i=1; i<=n; i++)if(st[i])res++;
    cout<<res;

}