#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN = 2e5;
int tree[mxN + 5];
void update(int index, int val) {
index++;
while(index < mxN + 5) {
tree[index] += val;
index += index & -index;
}
}
int query(int index) {
int ret = 0;
index++;
while(index > 0) {
ret += tree[index];
index -= index & -index;
}
return ret;
}
int rquery(int a, int b) {
if(b < a) return 0;
return query(b)-query(a-1);
}
long long count_swaps(vector<int> s) {
int n = s.size() / 2;
map<int, set<int>> inds;
for(int i = 0; i < 2 * n; ++i){
inds[s[i]].insert(i);
}
for(int i = 0; i < 2 * n; ++i){
update(i, 1);
}
bool left[2 * n];
fill(left, left + 2 * n, true);
long long ans = 0;
for(int i = 0; i < 2 * n; ++i){
if(!left[i]) continue;
int cur = s[i];
int first = *inds[-cur].begin();
left[first] = false;
ans += rquery(i + 1, first - 1);
if(cur > 0) ++ans;
update(first, -1);
inds[-cur].erase(inds[-cur].begin());
inds[cur].erase(i);
}
return ans;
}
