#include <bits/stdc++.h>
using namespace std;
#define int long long
int c[100005], d[100005];
signed main() {
int n, k;
int hp;
cin >> n >> k >> hp;
for (int i = 1; i <= n; i++) cin >> c[i] >> d[i];
int cnt = 0;
priority_queue <int> pq;
for (int i = 1; i <= n; i++) {
pq.push(c[i]);
while (cnt < k && hp <= d[i] && !pq.empty()) {
hp += pq.top();
pq.pop();
cnt++;
} hp -= d[i];
if (hp <= 0) {
cout << i - 1;
return 0;
}
} cout << n;
return 0;
}
