#include <bits/stdc++.h>
#include "shoes.h"
#define pii pair<int, int>
#define x first
#define y second
using namespace std;
const int N = 1e5 + 10;
vector<int> vec[2*N];
int n, arr[2*N], sz;
long long ans, fen[2*N];
long long query( int x ) {
long long ret = 0;
for( int i = x ; i > 0 ; i -= i & -i ) ret += fen[i];
return ret;
}
void up( int x ) {
for( int i = x ; i < 2*N ; i += i & -i ) fen[i] += 1;
}
long long count_swaps( vector<int> s ) {
n = s.size() / 2;
sz = s.size();
for( int i = 0 ; i < sz ; i++ ) vec[s[i]+N].emplace_back( i );
memset( arr, -1, sizeof arr );
for( int i = sz - 1 ; i >= 0 ; i-- ) {
if( arr[i] != -1 ) continue ;
vec[s[i]+N].pop_back();
int pos = vec[-1*s[i]+N].back(); vec[-1*s[i]+N].pop_back();
if( s[i] < 0 ) arr[i] = n*2-1, arr[pos] = n*2;
else arr[i] = n*2, arr[pos] = n*2-1;
n--;
//printf("%d %d %d %d\n",i,s[i],pos,s[pos]);
}
/*for( int i = 0 ; i < sz ; i++ ) printf("%d ",arr[i]);
printf("\n");*/
for( int i = sz-1 ; i >= 0 ; i-- ) {
//printf("%d ",arr[i]);
ans += query( arr[i] ), up( arr[i] );
}
return ans;
}
/*int main()
{
int ne;
vector<int> vec;
scanf("%d",&ne);
for( int i = 0, a ; i < ne ; i++ ) {
scanf("%d",&a);
vec.emplace_back( a );
}
printf("%lld",count_swaps( vec ) );
}*/
