#include<bits/stdc++.h>
using namespace std;
int solve(vector<int>&m,vector<int>&f){
    sort(m.begin(),m.end());
    sort(f.begin(),f.end());
    vector<int>mh,ml,fh,fl;
    for(int i=0;i<m.size();i++){
        if(m[i]<0){
            ml.push_back(abs(m[i]));
        }
        if(m[i]>=0){
            mh.push_back(abs(m[i]));
        }
    }
    for(int i=0;i<f.size();i++){
        if(f[i]<0){
            fl.push_back(abs(f[i]));
        }
        if(f[i]>=0){
            fh.push_back(abs(f[i]));
        }
    }
    int j=0,ans=0;
    for(int i=mh.size()-1;i>=0;i--){
        if(j>=fl.size())break;
        if(mh[i]<fl[j]){//male with higher height preference and female with low height preference
            ans++;j++;
        }
    }
    j=0;
    for(int i=fh.size()-1;i>=0;i--){
        if(j>=ml.size())break;
        if(fh[i]<ml[j]){//male with lower height preference and female with higher height preference
            ans++;j++;
        }
    }
    return ans;
    
}


int main(){
    int n;cin>>n;
    vector<int>m(n),f(n);
    for(int i=0;i<n;i++)cin>>m[i];
    for(int i=0;i<n;i++)cin>>f[i];
    cout<<solve(m,f)<<endl;
}