#include <bits/stdc++.h>
#include "books.h"
//#include "Lgrader.cpp"
using namespace std;
template<class T, class T2> inline int chkmax(T &x, const T2 &y) { return x < y ? x = y, 1 : 0; }
template<class T, class T2> inline int chkmin(T &x, const T2 &y) { return x > y ? x = y, 1 : 0; }
const int MAXN = (1 << 20);
int n;
int p[MAXN];
bool used[MAXN];
pair<int, int> dfs(int u)
{
used[u] = true;
pair<int, int> ret = {u, u};
if(!used[p[u]])
{
pair<int, int> oth = dfs(p[u]);
chkmax(ret.second, oth.second);
chkmin(ret.first, oth.first);
}
return ret;
}
long long minimum_walk(std::vector<int> p, int s)
{
if(s != 0) return -1;
n = p.size();
for(int i = 0; i < n; i++)
::p[i] = p[i];
int64_t answer = 0;
for(int i = 0; i < n; i++)
answer += abs(i - p[i]);
vector<pair<int, int> > li;
for(int i = 0; i < n; i++)
if(i != p[i] && !used[i])
li.push_back(dfs(i));
sort(li.begin(), li.end());
vector<pair<int, int> > tmp;
for(int i = 0; i < n; i++)
if(tmp.empty() || tmp.back().second < li[i].first) tmp.push_back(li[i]);
else chkmax(tmp[tmp.size() - 1].second, li[i].second);
int last = 0;
for(auto it: li)
{
answer += 2 * (it.first - last);
last = it.second;
}
return answer;
}
