#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
struct Fen { //0 based index
int n;
vector<int> bit;
Fen(int _n) : n(_n) {
bit = vector<int>(n+1);
}
void add(int i, int val) {
for(++i; i<=n; i+=i&-i) bit[i]+=val;
}
int sum(int i) { //[0, i]
int ans = 0;
for(++i; i>0; i-=i&-i) ans += bit[i];
return ans;
}
};
long long count_swaps(std::vector<int> s) {
int n = s.size()/2;
Fen fen(2*n+1);
vector<queue<int>> v(n+1);
long long ans = 0;
for(int i=1; i<=2*n; i++) {
int x = s[i-1];
int a = abs(x);
int sign = x / a;
if (v[a].empty()) {
v[a].push(i*sign); //i for right, -i for left
fen.add(i, 1);
} else {
int j = v[a].front();
if ((j<0 && x<0) || (j>0 && x>0)) {
v[a].push(i*sign);
fen.add(i, 1);
} else {
ans += (fen.sum(i) - fen.sum(abs(j)));
if (j>0) ans++;
fen.add(abs(j), 1);
v[a].pop();
}
}
}
return ans;
}
