#include<bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint=modint998244353; //1000000007;
using ll=long long;
using pp=pair<int,int>;
#define sr string 
#define vc vector
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define pque priority_queue
#define bpc(a) __builtin_popcount(a)
bool f(pp a,pp b){return a.se-b.fi>b.se-a.fi;}
int main(){
  int n;cin>>n;
  vc<pp>v(n); rep(i,n)cin>>v[i].fi>>v[i].se;
  sort(all(v),f);
  vc<ll>dp(n+1,-1e18); dp[0]=1e18;
  for(auto [a,b]:v){
    //cout<<a<<' '<<b<<"\n";
    for(int i=n;i>0;i--)if(dp[i-1]>=a)dp[i]=max(dp[i],min(dp[i-1]-a,(ll)b));
  }
  for(int i=n;i>0;i--)if(dp[i]>=0){
    cout<<i;
    return 0;
  }
}