#include<iostream>
#include<cmath>
#include<iomanip>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<vector>

#define ll long long
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
using namespace std;

void Fast_IO(){
    ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
    #endif
}





void solve(){

int n;
cin>>n;
vector<int>v;
int counter =0,ans=0;
for(int i =0; i<2*n; i++){
    int x; cin>>x;
    v.push_back(x);
}
for(int i = 0; i<2*n;i++){

    if(counter>ans) ans = counter;
    for(int j =0; j<i; j++){
    if(v[i]==v[j]) counter-=2;
    }
     counter++;
}

 cout<<ans;

}

int main(){
    Fast_IO();
int t =1;
//cin>>t;
while(t--){
solve();
}
return 0;
}