代码贴上

#include<bits/stdc++.h>
using namespace std;
int n,cnt;
struct Node{
	int len,hei;
}a[5010];
bool cmp(Node a,Node b)
{
	return a.len<=b.len&&a.hei<=b.hei;
}
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++) cin>>a[i].len>>a[i].hei;
	sort(a,a+n+1,cmp);
	int minn1=1e9,minn2=1e9;
	while(n--)
	{
		if(a[n].hei<=minn1&&a[n].len<=minn2) minn1=a[n].hei,minn2=a[n].len;
		else cnt++,minn1=a[n].hei,minn2=a[n].len;
	}
	cout<<cnt+1;
}