#include "books.h"
#include <bits/stdc++.h>
using namespace std;
map<pair<vector<int>, pair<int, int>>, int> memo;
int ans, START;
void solve(vector<int> p, int spot, int hold, int moves) {
if (moves >= ans) return;
if (memo.count({p, {spot, hold}}) && memo[{p, {spot, hold}}] <= moves) return;
memo[{p, {spot, hold}}] = moves;
bool ok = 1;
for (int i = 0; i < p.size(); i++) if (p[i] != i) ok = 0;
if (ok) {
ans = min(ans, moves + abs(START - spot));
return;
}
bool done = 0;
if (p[spot] != spot) swap(p[spot], hold), done = 1;
solve(p, spot, hold, moves);
if (done) swap(p[spot], hold);
if (spot - 1 >= 0) solve(p, spot - 1, hold, moves + 1);
if (spot + 1 < p.size()) solve(p, spot + 1, hold, moves + 1);
}
long long minimum_walk(vector<int> p, int s) {
START = s;
ans = 1e9;
solve(p, s, -1, 0);
return ans;
}
