#include <iostream>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <cstdlib>
#include <map>
#include <set>
#include <queue>
#include <vector>
using namespace std;
#define PAIR pair<long long, long long>

int main() {
	long long N; cin >> N;
	vector<long long> w(N), s(N);
	for (int i = 0; i < N; i++) cin >> w[i] >> s[i];

	vector<PAIR> sum(N);
	for (int i = 0; i < N; i++) {
		sum[i].first = w[i] + s[i];
		sum[i].second = w[i];
	}
	sort(sum.begin(), sum.end());

	vector<vector<long long>> dp(N + 1, vector<long long>(N + 1, 1LL << 60));
	for (int i = 0; i <= N; i++) {
		if (i == 0) {
			dp[i][0] = 0;
			continue;
		}
		for (int j = 0; j <= N; j++) {
			if (j == 0) dp[i][j] = 0;
			else {
				if (dp[i - 1][j - 1] > sum[i - 1].first - sum[i - 1].second) {
					dp[i][j] = dp[i - 1][j];
				}
				else {
					dp[i][j] = min(dp[i - 1][j], dp[i - 1][j - 1] + sum[i - 1].second);
				}
			}
		}
	}

	long long max_size = 0;
	for (int i = 1; i <= N; i++) {
		if (dp[N][i] != 1LL << 60) max_size = i;
	}

	cout << max_size << endl;
}