#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;

#define rep(i, n) for(int i = 0; i < (int)(n); ++i)

int op(int a, int b) {if(a > b) return a; return b;}
int e() {return -1e9;}

int main() {
	int N;
	cin >> N;
	vector<int> H(N);
	rep(i, N) cin >> H[i];
	
	{
		vector<pair<int, int>> cp(N);
		rep(i, N) cp[i] = {H[i], i};
		sort(cp.begin(), cp.end());
		rep(i, N) H[cp[i].second] = i + 1;
	}
	
	vector seg(4, segtree<int, op, e>(N + 2));
	auto chmax = [&](int i, int x, int val) {
		seg[i].set(x, max(seg[i].get(x), val));
	};
	
	auto affect = [&](int x, int sc) {
		chmax(0, x, seg[0].prod(x, N + 2) + sc);
		chmax(2, x, max(seg[1].prod(x, N + 2), seg[2].prod(x, N + 2)) + sc);
		for(auto i : {1, 3}) chmax(i, x, max(seg[i - 1].prod(0, x + 1), seg[i].prod(0, x + 1)) + sc);
	};
	
	seg[0].set(N + 1, 0);
	for(auto x : H) {
		affect(x, 1);
		affect(0, 0);
		affect(N + 1, 0);
	}
	
	cout << N - seg[3].all_prod() << "\n";
}