#include "bits/stdc++.h"
//#include "atcoder/all"
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
const long long LINF = 1e18;
//const bool debug = false;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<long long,long long>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
bool comp(const P& lh, const P& rh) {
	return lh.first + lh.second < rh.first + rh.second;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n; cin >> n;
	vector<P>p(n);
	rep(i, n) cin >> p[i].first >> p[i].second;
	sort(all(p), comp);
	vector<vector<long long>> dp(n + 1, vector<long long>(n + 1, LINF));
	dp[0][0] = 0;
	rep(i, n) {
		rep(j, n) {
			if (LINF == dp[i][j])continue;
			chmin(dp[i + 1][j], dp[i][j]);
			if (dp[i][j] <= p[i].second) {
				chmin(dp[i + 1][j + 1], dp[i][j] + p[i].first);
			}
		}
	}
	rrep(i, n + 1) {
		if (LINF != dp[n][i]) {
			cout << i << endl;
			return 0;
		}
	}
	return 0;
}