#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
#include <ctime>
#include <cstdlib>
using namespace std;

int solve_e_maxx(vector< pair< int ,int> > a, int n)
{
   sort(a.begin(), a.end());
   vector< int > res;
   set< pair<int , int > > se;
   for(int i = n-1; i >= 0; -- i)
   {
      int t = a[i].first-(i?a[i-1].first:0);
      se.insert( make_pair(a[i].second,i) );
      while(t && !se.empty())
      {
         set< pair<int,int> >::iterator it = se.begin();
         if(it->first <= t)
         {
            t-=it->first;
            res.push_back(it->second);
         }
         else
         {
            se.insert( make_pair(it->first-t, it->second) );
            t = 0;
         }
         se.erase(it);
      }
   }
   return res.size();
}

int solve_algo( vector< pair<int, int> > a, int n)
{
   sort(a.begin(), a.end());
   set< pair<int , int > > se;
   int T = 0;
   for(int i = 0; i < n; ++ i)
   {
      if(T+a[i].second <= a[i].first)
      {
         T+=a[i].second;
         se.insert( make_pair( -a[i].second ,i) );
      }
      else
      if(!se.empty())
      {
         set< pair<int, int> >::iterator it = se.begin();
         if(-(it->first) > (a[i].second))
         {
            T = T+(a[i].second)-(-(it->first));
            se.erase(it);
            se.insert( make_pair(-a[i].second, i));
         }
      }
   }
   return se.size();
}

int main()
{
   srand(time(NULL));
   freopen("input.txt", "r", stdin);
   freopen("output.txt", "w", stdout);
   int n;
/*   while(1)
   {
    n = rand()%100+1;*/
      cin>>n;

      vector< pair<int, int > > a(n);
   /*   for(int i = 0; i < n; ++ i)
      {
         a[i].first = rand()%10000+1;
         a[i].second = rand()%(10000)+1;
      }*/

      for(int i = 0;i < n; ++ i)
      {
         cin>>(a[i].first)>>(a[i].second);//completion, duration
      }

      int re1 = solve_e_maxx(a, n);
      int re2 = solve_algo(a, n);
   //   cout<<re1<<" "<<re2<<endl;


      if(re1!=re2)
      {
         cerr<<"Wrong answer\n";
         cout<<n<<endl;
         for(int i = 0; i < n; ++ i)
         {
            cout<<a[i].first<<" "<<a[i].second<<endl;
         }
     //    break;
      }
  //}
   return 0;
}