#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long LL;
const int N = 3e3+10,mod = 1e9+7;
LL f[N][N];
struct Node{
	LL a,b;
	bool operator<(const Node &A)const{
		return a+b<A.a+A.b;
	}
}a[N];
int main(){
	int n;
	scanf("%d",&n);
	for(int i=1;i<=n;i++){
		scanf("%d%d",&a[i].a,&a[i].b);
	}
	sort(a+1,a+1+n);
	memset(f,0x3f,sizeof f);
	f[0][0]=0;
	LL INF = f[1][1];
	int ans=0;
	for(int i=1;i<=n;i++){
		f[i][0]=0;
		for(int j=1;j<=i;j++){
			f[i][j]=min(f[i-1][j],f[i][j]);
			if(a[i].b>=f[i-1][j-1]){
				f[i][j]=min(f[i][j],f[i-1][j-1]+a[i].a);
				ans=max(ans,j);
			}
		}
	}
	cout<<ans;
	return 0;
}