#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<cmath>

#include<queue>

using namespace std;

#define MAXN 150010

priority_queue<int>q;

int n;

int i;

int res,ans,tmp;

struct Node

{

    int t,d;

}a[MAXN];

int cmp(Node x,Node y)

{

    return x.d<y.d;

}

int main()

{

    scanf("%d",&n);

    for (i=1;i<=n;i++)

        scanf("%d%d",&a[i].t,&a[i].d);

    sort(a+1,a+n+1,cmp);

    for (i=1;i<=n;i++)

        if (res+a[i].t<=a[i].d)

        {

            ans++;

            res+=a[i].t;

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

        }

        else

        {

            tmp=q.top();

            if (a[i].t<tmp)

            {

                q.pop();

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

                res+=a[i].t-tmp;

            }

        }

    printf("%d",ans);

    return 0;

}