#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 100000000000000000

int main(){
	
	int N;
	cin>>N;
	vector<long long> w(N),s(N);
	vector<pair<long long,int>> p;
	rep(i,N){
		cin>>w[i]>>s[i];
		p.emplace_back(w[i]+s[i],i);
	}
	
	sort(p.begin(),p.end());
	
	vector<long long> dp(N+1,Inf);
	dp[0] = 0;
	
	rep(i,N){
		long long ww = w[p[i].second],ss = s[p[i].second];
		
		vector<long long> ndp(N+1,Inf);
		rep(j,N+1){
			ndp[j] = min(ndp[j],dp[j]);
			if(j!=N && dp[j]<=ss){
				ndp[j+1] = min(ndp[j+1],dp[j] + ww);
			}
		}
		swap(dp,ndp);
	}
	
	int ans = 0;
	rep(i,N+1){
		if(dp[i]!=Inf)ans = i;
	}
	cout<<ans<<endl;
	
	
	
    return 0;
}