#include<cstdio>

 #include<cstring>

 #include<cstdlib>

 #include<cmath>

 #include<algorithm>

 #include<queue>

 #include<vector>

 using namespace std;

 typedef long long LL;

 struct node

 {

     LL t1,t2;

 }a[];

 priority_queue<int,vector<int>,less<int> > q;

 bool cmp(node n1,node n2)

 {

     if(n1.t2>n2.t2)return false;

     if(n1.t2<n2.t2)return true;

     if(n1.t1<n2.t1)return true;

     if(n1.t1>n2.t1)return false;

     return true;

 }

 LL n;

 int main()

 {

     scanf("%lld",&n);

     for(int i=;i<=n;i++)

         scanf("%lld%lld",&a[i].t1,&a[i].t2);

     sort(a+,a+n+,cmp);

     LL ans=,now=;

     for(int i=;i<=n;i++)

     {

         if(now+a[i].t1<=a[i].t2)

         {

             ans++;

             now+=a[i].t1;

             q.push(a[i].t1);

         }

         else

         {

             LL t=q.top();

             if(a[i].t1<t)

             {

                 q.pop();

                 now-=t-a[i].t1;

                 q.push(a[i].t1);

             }

         }

     }

     printf("%lld\n",ans);

     return ;

 }