#pragma GCC optimize(2)

 #include <algorithm>

 #include <cstdio>

 #include <functional>

 #include <set>

 #define REP(i,low,high) for(register int i=(low);i<=(high);i++)

 using namespace std;

 struct node

 {

     int ft,et;

     node() {}

     int input() {return scanf("%d%d",&ft,&et);}

     bool operator<(const node &another)const{return et<another.et;}

 }a[];

 int n;

 multiset<int, greater<int> > sav;

 int main()

 {

     scanf("%d",&n),sav.clear(); REP(i,,n) a[i].input(); sort(a+,a+n+);

     int ans=,now=;

     REP(i,,n)

     {

         if(a[i].ft+now<=a[i].et) sav.insert(a[i].ft),ans++,now+=a[i].ft;

         else

         {

             multiset<int>::iterator tp=sav.begin();

             if(*tp>a[i].ft) now+=a[i].ft-*tp,sav.erase(tp),sav.insert(a[i].ft);

         }

     }

     return printf("%d\n",ans),;

 }