#include<iostream>
#include<algorithm>//sort
#include<queue>//小根堆
using namespace std;
const int N=100010;
int n;
struct Range
{
int l,r;
bool operator < (const Range &W)const
{
return l<W.l;
}
}range[N];
int main()
{
scanf("%d",&n);
for (int i=0;i<n;i++)
{
int l,r;
scanf("%d%d",&l,&r);
range[i]={l,r};
}
sort(range,range+n);
priority_queue<int, vector<int>,greater<int> >heap;//写法
for(int i=0;i<n;i++)
{
auto r=range[i];
if(heap.empty()||heap.top()>=r.l) heap.push(r.r);//为空或者不满足创新组
else
{
int t=heap.top();
heap.pop();
heap.push(r.r);
}
}
printf("%d\n",heap.size());
return 0;
}
