#include <bits/stdc++.h>
#define int long long
using namespace std;
const int INF = 1e9;
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int n;
cin >> n;
vector<int> a(n);
for (auto& el : a)
cin >> el;
int curnondec = 0;
vector<int> dp(n, INF);
multiset<int> se;
for (int i = 0; i < n; ++i) {
if (i == 0 || a[i] < a[i - 1])
curnondec = 1;
else
curnondec += 1;
se.insert(a[i]);
for (int j = i - 1; j >= i - curnondec; --j) {
se.extract(a[j + 1]);
int mx = a[i], mn = a[j + 1];
auto it = se.lower_bound(mx);
if (it == se.begin() || *prev(it) <= mn) {
dp[i] = min(dp[i], (j == -1 ? 1ll : dp[j] + 1));
}
}
for (int j = i - curnondec + 1; j <= i; ++j)
se.insert(a[j]);
}
cout << dp.back();
}
