#include <iostream>
#include <vector>
#include <queue>
#include <stack>
#include <functional>
#include <algorithm>

using namespace std;

#define N 150010
#define ull unsigned long long
#define ll long long
#define debug(i) cout<<i<<endl;

#define rep(i,s,e) for(int i = s;i <= e;i++)
#define rep1(i,s,e) for(int i = 1;i <= e;i++)
#define rep0(i,s,e) for(int i = 0;i < e;i++)
#define get(a,b,c,x) a*x*x+b*x+c

ll n;
ll ans;
ll sum;

struct build
{
	ll T1,T2;
	void input(){cin >> T1 >> T2;}
	void print(){printf("T1 = %lld T2 = %lld\n",T1,T2);}
}a[N];

bool cmp(build a,build b){return a.T2 < b.T2;}

bool operator<(build const &a,build const &b){return a.T2<b.T2;}
bool operator>(build const &a,build const &b){return a.T2>b.T2;}

priority_queue<build,vector<build>,less<build> > q;

int main()
{
	cin >> n;
	rep(i,1,n) a[i].input();
	//rep(i,1,n) a[i].print();
	//cout<<"\n";
	sort(a+1,a+n+1,cmp);
	//rep(i,1,n) a[i].print();
	rep(i,1,n)
	{
		sum+=a[i].T1;
		q.push(a[i]);
		if(sum<=a[i].T2)ans++; 
		else 
		{
			sum-=q.top().T1;
			q.pop();
		}
	}
	cout<<ans;
	return 0;
}

30pts