#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;
using ll = long long;


int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n;
    cin>>n;
    vector<ll> w(n),s(n);
    for(int i = 0;i<n;i++) cin>>w[i]>>s[i];
    vector<int> idx(n);
    for(int i = 0;i<n;i++) idx[i] = i;
    sort(idx.begin(),idx.end(),[&](int i,int j){
        if(s[i]+w[i]!=s[j]+w[j]) return s[i] + w[i] < s[j] + w[j];
        return s[i] > s[j];
    });
    vector<vector<ll>> dp(n+1,vector<ll>(n+1,1e18));
    dp[0][0] = 0;
    for(int i = 0;i<n;i++){
        int ni = idx[i];
        for(int j = 0;j<=n;j++){
            dp[i+1][j] = min(dp[i][j],dp[i+1][j]);
            if(j==n) continue;
            if(dp[i][j]<=s[ni]){
                dp[i+1][j+1] = min(dp[i+1][j+1],dp[i][j]+w[ni]);
            }
        }
    }
    for(int i = n;i>=0;i--){
        if(dp[n][i]!=1e18){
            cout<<i<<endl;
            return 0;
        }
    }

}