#include <bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pii pair<int, int>
#define all(x) x.begin(), x.end()
#define rep(i, a, b) for (int i = (int)a; i <= (int)b; ++i)
#define rep1(i, a, b) for (int i = (int)a; i >= (int)b; --i)
#define mp make_pair
const int N = 2e5 + 5;
const int k = 19;
int L[N][20], R[N][20], higher[N][20], h[N];
int my_size;
bool sub1 = 1;
void cal_LR() {
rep(i, 1, my_size) if (h[i] != i) {
sub1 = 0;
break;
}
if (sub1) return;
stack<int> st;
rep(i, 1, my_size) {
while (!st.empty() && h[st.top()] < h[i]) st.pop();
if (!st.empty()) L[i][0] = st.top();
st.push(i);
}
while (!st.empty()) st.pop();
rep1(i, my_size, 1) {
while (!st.empty() && h[st.top()] < h[i]) st.pop();
if (!st.empty()) R[i][0] = st.top();
st.push(i);
}
rep(i, 1, my_size) {
if (h[L[i][0]] > h[R[i][0]]) higher[i][0] = L[i][0];
else higher[i][0] = R[i][0];
}
rep(u, 1, k) {
rep(i, 1, my_size) {
L[i][u] = L[L[i][u - 1]][u - 1];
R[i][u] = R[R[i][u - 1]][u - 1];
higher[i][u] = higher[higher[i][u - 1]][u - 1];
}
}
}
int minimum_jumps_sub1234(int a, int b, int c, int d) {
if (sub1) return c - b;
++a, ++b, ++c, ++d;
queue<pii> q;
vector<bool> vst(my_size + 1);
vst[0] = 1;
rep(i, a, b) q.push({i, 0}), vst[i] = 1;
while (!q.empty()) {
auto [u, w] = q.front();
q.pop();
if (c <= u && u <= d) return w;
int v = L[u][0];
if (!vst[v]) {
q.push({v, w + 1});
vst[v] = 1;
}
v = R[u][0];
if (!vst[v]) {
q.push({v, w + 1});
vst[v] = 1;
}
}
return -1;
}
int minimum_jumps_sub5(int s, int t) {
++s, ++t;
int ans = 0;
//cout << "s,H,L,R="<<s<<' '<<higher[s][0] << ' ' << L[s][0] << ' ' << R[s][0] << '\n';
rep1(u, k, 0) {
if (higher[s][u] != 0 && h[higher[s][u]] <= h[t]) {
ans += (1 << u);
s = higher[s][u];
}
}
if (s != t) {
//cout << "s,ans,R0="<<s<<' '<<ans<<' '<<R[s][0]<<'\n';
rep1(u, k, 0) {
if (R[s][u] != 0 && h[R[s][u]] <= h[t]) {
ans += (1 << u);
s = R[s][u];
}
}
}
if (s != t) {
return -1;
}
else return ans;
}
int minimum_jumps(int a, int b, int c, int d) {
//if (a == b && c == d) return minimum_jumps_sub5(a, c);
return minimum_jumps_sub1234(a, b, c, d);
}
void init(int sz, vector<int> array) {
my_size = sz;
rep(i, 1, my_size) h[i] = array[i - 1];
cal_LR();
}
