#include "shoes.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef int64_t ll;
typedef string str;
#define ordered_set tree <int, null_type, less <int>, rb_tree_tag, tree_order_statistics_node_update>
long long count_swaps(vector <int> S) {
int n = (int)S.size();
ll ans = 0;
for (int i = 0; i < n; ++i) {
S[i] += n;
}
vector <deque <int>> pos(2 * n + 1);
vector <bool> used(n, false);
ordered_set st;
for (int i = 0; i < n; ++i) {
pos[S[i]].push_back(i);
}
for (int i = 0; i + 1 < n; ++i) {
if (used[i]) {
continue;
}
if (S[i] > n) {
int left = S[i] - n - 2 * (S[i] - n) + n, right = S[i];
int from = pos[left].front();
ans += from - i;
ans -= (int)st.order_of_key(from + 1) - (int)st.order_of_key(i);
st.insert(i), st.insert(from);
used[i] = true, used[from] = true;
pos[left].pop_front(), pos[right].pop_front();
} else {
int left = S[i], right = S[i] - n - 2 * (S[i] - n) + n;
int from = pos[right].front();
ans += from - i - 1;
ans -= (int)st.order_of_key(from + 1) - (int)st.order_of_key(i);
st.insert(i), st.insert(from);
used[i] = true, used[from] = true;
pos[left].pop_front(), pos[right].pop_front();
}
}
return ans;
}
