#include "optimization.h"
#include <iostream>
#include <string>
#include <algorithm>
#include <cstdio>
#include <vector>
#include <queue>
#include <set>
#include <bitset>
#include <unordered_map>
#include <cassert>
#include <cstring>
#include <time.h>
#include <math.h>
#include <random>
#include <unordered_map>
#include <functional>


using namespace std;


/// custom defines

#define IS_FIN_FOUT__
#define INFILE "file"

//#define IS_TEST

typedef int64_t ll;
typedef __uint128_t bll;
typedef uint64_t ull;
typedef __uint128_t ubll;
#define ff first
#define ss second
#define array_bounds(a) a.begin(), a.end()

/// end custom defines

vector<pair<int, int>> boxes;

int main() {

#ifdef IS_FIN_FOUT__
  freopen(INFILE".in", "r", stdin);
  freopen(INFILE".out", "w", stdout);
#endif

  int n = readInt();

  for (int i = 0; i < n; ++i) {
    boxes.push_back({readInt(), readInt()});
  }

  sort(boxes.begin(), boxes.end(), [](auto lhs, auto rhs) -> bool {
    return lhs.first + lhs.second < rhs.first + rhs.second;
  });

  auto compare = [](auto &lhs, auto &rhs) -> bool {
    return lhs.first > rhs.first;
  };

  set<pair<int, int>, decltype(compare)> heap(compare);

  uint64_t weight = 0;

  for (auto box : boxes) {
    if (box.second >= weight) {
      heap.insert(box);
      weight += box.first;
    } else {
      if (box.first < heap.begin()->first) {
        weight -= heap.begin()->first;
        heap.erase(heap.begin());

        heap.insert(box);
        weight += box.first;
      }
    }
  }

  writeInt(heap.size());

  return 0;
}