#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5;
int tree[2*N + 5];
set<pair<int, int>> f, se;
void update(int n, int k, int v) {
for (; k <= n; k += k&-k) tree[k] += v;
}
int query(int k) {
int sum = 0;
for (; k; k -= k&-k) sum += tree[k];
return sum;
}
long long count_swaps(std::vector<int> s) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n = s.size()/2;
s.insert(s.begin(), 0);
for (int i = 1; i <= 2*n; i++) {
f.insert({i, s[i]});
se.insert({s[i], i});
}
int index = 1;
long long ans = 0;
while (f.size()) {
pair<int, int> lef = *f.begin();
f.erase(f.begin());
se.erase({lef.second, lef.first});
pair<int, int> rig = *se.lower_bound({-lef.second, 0});
se.erase(rig);
f.erase({rig.second, rig.first});
if (lef.second > 0) ans++;
int cur = rig.second + query(2*n) - query(rig.second - 1);
ans += (long long)cur - index - 1;
update(2*n, rig.second, 1);
index += 2;
}
return ans;
}
/*signed main() {
int n;
cin >> n;
vector<signed> arr(2*n);
for (int i = 0; i < 2*n; i++) cin >> arr[i];
cout << count_swaps(arr) << '\n';
return 0;
}*/
