F315 V1

#include<bits/stdc++.h>
using namespace std;

//#define endl '\n'
#define ll long long
#define pii pair<int, int>
#define mp make_pair
#define F first
#define S second
#define pb push_back
#define pog ios::sync_with_stdio(0);
#define champ cin.tie(0);
#define inf 2147483647

struct Node{
	int val;
	int l, r;
	int lson, rson;
};

const int N = 100000 + 5;
Node st[2*N];
int a[2*N];
int st_ptr = 0;
int visit[N];


void build(int l, int r, int index){
	st[index].l = l; st[index].r = r;
	if(l + 1 == r){
		st[index].val = 0;
		return;
	}

	int mid = (l + r) / 2;
	st[index].lson = ++st_ptr;
	st[index].rson = ++st_ptr;

	build(l, mid, st[index].lson);
	build(mid, r, st[index].rson);

	st[index].val = st[st[index].lson].val + st[st[index].rson].val;
}

void increment(int x, int index){
	if(st[index].l + 1 == st[index].r){
		st[index].val++;
		return;
	}

	int mid = (st[index].l + st[index].r)/2;

	if(x>=mid){
		increment(x, st[index].rson);
	}
	else{
		increment(x, st[index].lson);
	}

	st[index].val = st[st[index].lson].val + st[st[index].rson].val;
}

int query(int l, int r, int index){
	if(st[index].l == l && st[index].r == r){
		return st[index].val;
	}

	int mid = (st[index].l + st[index].r) / 2;

	if(r <= mid){
		return query(l, r, st[index].lson);
	}
	else if(l >= mid){
		return query(l, r, st[index].rson);
	}
	else{
		return query(l, mid, st[index].lson) + query(mid, r, st[index].rson);
	}

}
void solve(){
	int n; cin >> n;
	for(int i = 0; i < 2 * n; i++){
		cin >> a[i];
	}

	build(0, n+1, 0);
	//cout << "BUILD COMPLETE" << endl;

	ll int sol = 0;

	for(int i = 0; i < 2 * n; i++){
		if(!visit[a[i]]){
			sol -= query(0, a[i], 0);
		}
		else{
			sol += query(0, a[i]+1, 0)-1;
		}
		increment(a[i], 0);
		visit[a[i]] = true;
	}

	cout << sol << endl;
}

int main(){
	pog champ
	solve();
}