测试点#1#9WA,求各位大佬帮帮本蒟蒻

#include<bits/stdc++.h>
using namespace std;
int n,ans,now;
struct node
{
	int begin,end;
	friend bool operator<(const node& a,const node& b)
	{
		return a.end<b.end;
	}
	friend istream& operator>>(istream& in,node& n)
	{
		in>>n.begin>>n.end;
		return in;
	}
}a[1000005];
int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++)
		scanf("%d%d",&a[i].begin,&a[i].end);
	sort(a+1,a+n+1);
	ans++,now=a[1].begin;
	for(int i=2;i<=n;i++)
	{
		if(a[i].begin>=now)
		{
			ans++;
			now=a[i].end;
		}
	}
	cout<<ans<<endl;
	return 0;
}