#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define clz __builtin_clzll
#define ctz __builtin_ctzll
#define popcount __builtin_popcount
#define lg(x) (63 - clz(x))
template <class X, class Y>
inline bool maximize(X &x, Y y) {
return (x < y ? x = y, true : false);
}
template <class X, class Y>
inline bool minimize(X &x, Y y) {
return (x > y ? x = y, true : false);
}
template <class X>
inline void compress(vector<X> &a) {
sort(all(a)); a.resize(unique(all(a)) - a.begin());
}
const ll oo = (ll) 1e18, inf = (ll) 1e9, mod = (ll) 1e9 + 7;
const int mxn = (int) 1e6 + 10, S = (int) 450, S2 = (int) 450, lg = (int) 18;
void add(ll &x, ll y) {
x += y;
if (x >= mod) x -= mod;
}
void sub(ll &x, ll y) {
x -= y;
if (x < 0) x += mod;
}
int n;
int a[mxn];
namespace one {
bool one() {
return n <= 1e3;
}
const int mxn = (int) 1e3 + 5;
int f[mxn];
vector<int> cur[mxn];
void solve() {
memset(f, 0x3f, sizeof f);
f[0] = 0;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= i; ++j)
cur[i].push_back(a[j]);
compress(cur[i]);
}
for (int i = 1; i <= n; ++i) {
f[i] = f[i-1] + 1;
for (int j = i-1; j >= 1; --j) {
if (a[j] > a[j+1]) break;
if (a[i] == a[j]) {
minimize(f[i], f[j-1] + 1);
continue;
}
int cnt = upper_bound(all(cur[j-1]), a[i] - 1) - lower_bound(all(cur[j-1]), a[j] + 1);
if (cnt != 0) break;
minimize(f[i], f[j-1] + 1);
}
}
cout << f[n];
return;
}
}
namespace two {
bool two() {
return true;
}
struct Seg {
int n;
vector<int> st;
Seg(int n) : n(n) {
st.resize(n << 2);
}
void upd(int p, int x) {
int i = 1;
for (int l = 1, r = n; l < r; ) {
int m = (l + r) >> 1;
if (p > m) {
l = m + 1;
i = 2 * i + 1;
}
else {
r = m;
i = 2 * i;
}
}
st[i] += x;
while (i > 1) {
i >>= 1;
st[i] = st[2 * i] + st[2 * i + 1];
}
}
int get(int i, int l, int r, int u, int v) {
if (l > v || r < u) return 0;
if (l >= u && r <= v) return st[i];
int m = (l + r) >> 1;
int L = get(2 * i, l, m, u, v);
int R = get(2 * i + 1, m + 1, r, u, v);
return L + R;
}
int get(int u, int v) {
if (u > v) return 0;
return get(1, 1, n, u, v);
}
};
int f[mxn];
void solve() {
int mx = a[max_element(a + 1, a + 1 + n) - a];
Seg s(mx);
memset(f, 0x3f, sizeof f);
f[0] = 0;
for (int i = 1, j = 1; i <= n; ++i) {
while (j < i && a[i] < a[i-1]) {
s.upd(a[j], 1); j++;
}
while (j < i && s.get(a[j] + 1, a[i] - 1) != 0) {
s.upd(a[j], 1); j++;
}
minimize(f[i], f[j-1] + 1);
}
cout << f[n];
return;
}
}
void solve() {
cin >> n;
for (int i = 1; i <= n; ++i)
cin >> a[i];
{
// if (one::one()) return one::solve();
if (two::two()) return two::solve();
}
return;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define TASK "task"
if (fopen(TASK".inp", "r")) {
freopen(TASK".inp", "r", stdin);
freopen(TASK".out", "w", stdout);
}
int t = 1;
// cin >> t;
while (t--) {
solve();
}
return 0;
}
