#include<bits/stdc++.h>
#pragma optimize ("g",on)
#pragma GCC optimize ("inline")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize ("03")
#pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
#pragma comment(linker, "/stack:200000000")
//01001101 01100001 01101011 01101000 01100001 01100111 01100001 01111001
using namespace std;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ll long long
#define pb push_back
#define sz(a) a.size()
#define nl '\n'
#define popb pop_back()
#define ld double
#define ull unsigned long long
#define ff first
#define ss second
#define fix fixed << setprecision
#define pii pair<int, int>
#define E exit (0)
#define int long long
const int inf = 1e18, N = 1e6 + 1, mod = 998244353;
vector<pii> dir = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
vector<int> t(4 * N, inf);
void update(int u, int tl, int tr, int l, int r, int val) {
if (tl > r || tr < l) return;
if (tl >= l && tr <= r) {
t[u] = min(t[u], val);
return;
}
int mid = (tl + tr) / 2;
update(u * 2, tl, mid, l, r, val);
update(u * 2 + 1, mid + 1, tr, l, r, val);
}
int get(int u, int tl, int tr, int pos) {
if (tl == tr) return t[u];
int mid = (tl + tr) / 2;
if (pos <= mid) {
return min(get(u * 2, tl, mid, pos), t[u]);
}
return min(get(u * 2 + 1, mid + 1, tr, pos), t[u]);
}
main() {
//freopen("cowrect.in", "r", stdin);
//freopen("cowrect.out", "w", stdout);
ios_base::sync_with_stdio(NULL);
cin.tie(NULL);
int n;
cin >> n;
int a[n + 1], r[n + 1];
for (int i = 1; i <= n; i++) cin >> a[i];
int l = 1;
for (int i = 2; i <= n; i++) {
if (a[i] < a[i - 1]) {
while (l < i) {
r[l++] = i - 1;
}
}
}
while (l <= n) {
r[l++] = n;
}
set<int> s;
update(1, 0, n, 0, 0, 0);
for (int i = 1; i <= n; i++) {
auto it = s.upper_bound(a[i]);
int val;
if (it == s.end()) val = inf;
else val = *it;
int tl = i, tr = r[i], pos;
while (tl <= tr) {
int mid = (tl + tr) / 2;
if (a[mid] <= val) {
tl = mid + 1;
pos = mid;
}else tr = mid - 1;
}
update(1, 0, n, i, pos, get(1, 0, n, i - 1) + 1);
s.insert(a[i]);
}
cout << get(1, 0, n, n);
}
