#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main() {
	const ll INF = 1e18;
	ll L;
	cin >> L;
	vector<ll> A(L + 1);
	for (int i = 1; i <= L; ++i) { cin >> A[i]; }

	vector<vector<ll>> dp(L + 1, vector<ll>(5, INF));
	dp[1][0] = A[1];
	dp[1][1] = A[1] % 2;
	if (A[1] == 0) { dp[1][1] = 2; }
	dp[1][2] = 1 - (A[1] % 2);
	for (int i = 2; i <= L; ++i) {
		for (int j = 0; j < 5; ++j) {
			ll tmp = INF;
			for (int k = 0; k <= j; ++k) { tmp = min(tmp, dp[i - 1][k]); }

			dp[i][j] = tmp;
			if ((j == 0) || (j == 4)) { dp[i][j] += A[i]; }
			if ((j == 1) || (j == 3)) { 
				if (A[i] == 0) { dp[i][j] += 2; }
				else { dp[i][j] += (A[i] % 2); }
			}
			if (j == 2) {
				dp[i][j] += (1 - (A[i] % 2));
			}
		}
	}

	ll res = INF;
	for (int i = 0; i < 5; ++i) { res = min(res, dp[L][i]); }

	cout << res << endl;

	return 0;
}
