#include <bits/stdc++.h>
using namespace std;
const long long INF = 1000000000000000;
int main(){
  int N;
  cin >> N;
  vector<int> w(N), s(N);
  for (int i = 0; i < N; i++){
    cin >> w[i] >> s[i];
  }
  vector<tuple<int, int, int>> T(N);
  for (int i = 0; i < N; i++){
    T[i] = make_tuple(s[i] + w[i], s[i], w[i]);
  }
  sort(T.begin(), T.end());
  for (int i = 0; i < N; i++){
    s[i] = get<1>(T[i]);
    w[i] = get<2>(T[i]);
  }
  vector<vector<long long>> dp(N + 1, vector<long long>(N + 1, INF));
  dp[0][0] = 0;
  for (int i = 0; i < N; i++){
    dp[i + 1] = dp[i];
    for (int j = 0; j <= i; j++){
      if (dp[i][j] <= s[i]){
        dp[i + 1][j + 1] = min(dp[i + 1][j + 1], dp[i][j] + w[i]);
      }
    }
  }
  long long ans = 0;
  for (int i = 0; i <= N; i++){
    if (dp[N][i] != INF){
      ans = i;
    }
  }
  cout << ans << endl;
}