#include <bits/stdc++.h>
using namespace std;
struct node{
    long long c,m;
}s[200005];
long long n,k,p,ans,i,j,z;
int main()
{
    cin>>n>>k>>p;
    for(i=1;i<=n;i++)cin>>s[i].c>>s[i].m;
    for(i=1;i<n;i++){
        for(j=i+1;j<=n;j++){
            if(s[i].c==s[j].c)
            {
                long long minn=2147483647;
                for(z=i;z<=j;z++)minn=min(minn,s[z].m);
                if(minn<=p)ans++;
            }
        }
    }
    cout<<ans;
    return 0;
}