#include "books.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef complex<ld> point;
void debug_out(){cerr << endl;}
template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T){
cerr << H << ' ';
debug_out(T...);
}
#define debug(...) cerr << "(" << #__VA_ARGS__ << "): ", debug_out(__VA_ARGS__)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)
const int maxn = 1e6 + 10;
int n, cnt[maxn][2];
ll minimum_walk(vector<int> p, int s) {
n = p.size();
int mn = s, mx = s;
for (int i = 0; i < n; i++){
if (p[i] == i) continue;
mn = min(mn, i);
mx = max(mx, i);
if (p[i] < i){
//debug(p[i]+1, i);
cnt[p[i]+1][0]++;;
cnt[i+1][0]--;
}
else{
//debug(i+1, p[i]);
cnt[i+1][1]++;
cnt[p[i]+1][1]--;
}
}
//debug(cnt[mn][0], cnt[mn][1]);
for (int i = mn+1; i <= mx; i++){
//debug(i, cnt[i][0], cnt[i][1]);
}
//debug(mn, mx);
ll ans = 0;
for (int i = mn+1; i <= mx; i++){
cnt[i][0] += cnt[i-1][0];
cnt[i][1] += cnt[i-1][1];
//debug(i, cnt[i][0], cnt[i][1]);
if (cnt[i][0] == 0){
cnt[i][0]++;
cnt[i+1][0]--;
}
if (cnt[i][1] == 0){
cnt[i][1]++;
cnt[i+1][1]--;
}
ans += 2 * max(cnt[i][0], cnt[i][1]);
}
return ans;
return 0;
}
