#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
struct Gym {
int levelCap;
int levelGain;
};
// Comparator for sorting gyms by level cap
bool compareGyms(const Gym &a, const Gym &b) {
return a.levelCap < b.levelCap;
}
int maxBadges(vector<Gym> &gyms) {
sort(gyms.begin(), gyms.end(), compareGyms); // Sort gyms by level cap
priority_queue<int> pq; // Max-heap to store level gains
int currentLevel = 0, badgeCount = 0, i = 0, n = gyms.size();
while (i < n || !pq.empty()) {
// Add all gyms that are available to challenge
while (i < n && gyms[i].levelCap >= currentLevel) {
pq.push(gyms[i].levelGain);
i++;
}
// If no gym can be challenged, break
if (pq.empty()) break;
// Challenge the gym with the highest level gain
currentLevel += pq.top();
pq.pop();
badgeCount++;
}
return badgeCount;
}
int main() {
int N;
cin >> N;
vector<Gym> gyms(N);
for (int i = 0; i < N; i++) {
cin >> gyms[i].levelCap >> gyms[i].levelGain;
}
cout << maxBadges(gyms) << endl;
return 0;
}
