#include<bits/stdc++.h>
using namespace std;
main(){
int n;
cin>>n;
vector<int>male(n),female(n);
for(auto &it:male)cin>>it;
for(auto &it:female)cin>>it;
sort(male.begin(),male.end());
sort(female.begin(),female.end());
int i=0,j=n-1,cnt=0;
while(i<n&&j>=0){
if(male[i]<=0&&female[j]>=0){
if(abs(male[i])>female[j]){
cnt++;
i++;
j--;
}
else j--;
}
else if(male[i]>=0&&female[j]<=0){
if(male[i]<abs(female[j])){
cnt++;
i++;
j--;
}
else j--;
}
else{
i++;
}
}
cout<<cnt<<"\n";
}
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