#include<bits/stdc++.h>
using namespace std;
vector<int> b1,b2,g1,g2;
int n,x,num,pos,ans; 
int main(){
	cin>>n; 
	for(int i=1;i<=n;i++){
		cin>>x; 
		if(x>0) b1.push_back(x);
		else b2.push_back(-x);
	}
	for(int i=1;i<=n;i++){
		cin>>x;
		if(x>0) g1.push_back(x);
		else g2.push_back(-x);
	}
	sort(b1.begin(),b1.end());
	sort(b2.begin(),b2.end());
	sort(g1.begin(),g1.end());
	sort(g2.begin(),g2.end());
	for(int i=0;i<b1.size();i++){
		num=b1[i],pos=upper_bound(g2.begin(),g2.end(),num)-g1.begin();
		if(pos<(g2.size())&&g2[pos]>num) g2.erase(g2.begin()+pos),ans++;
	}
	for(int i=0;i<b2.size();i++){
		num=b2[i];
		if(g1.size()>0&&g1[0]<num) g1.erase(g1.begin()),ans++;
	}
	cout<<ans;
	return 0;
}

看了题解，挺像第一篇的