#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i= (a); i<((int)b); ++i)
#define RFOR(i,a) for(int i=(a); i >= 0; --i)
#define FOE(i,a) for(auto i : a)
#define ALL(c) (c).begin(), (c).end()
#define RALL(c) (c).rbegin(), (c).rend()
#define DUMP(x)  cerr << #x << " = " << (x) << endl;
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v,x) (std::find(v.begin(), v.end(), x) != v.end())
#define BIT_ON(bit, i) (bit & (1LL << i))
#define BIT_COUNT(bit) (__builtin_popcount(bit))

typedef long long LL;
template<typename T> using V = std::vector<T>;
template<typename T> using VV = std::vector<std::vector<T>>;
template<typename T> using VVV = std::vector<std::vector<std::vector<T>>>;
template<typename T> using VVVV = std::vector<std::vector<std::vector<std::vector<T>>>>;

template<class T> inline T ceil(T a, T b) { return (a + b - 1) / b; }
template<class T> inline void print(T x) { std::cout << x << std::endl; }
template<class T> inline void print_vec(const std::vector<T> &v) { for (int i = 0; i < v.size(); ++i) {  if (i != 0) {std::cout << " ";} std::cout << v[i];} std::cout << "\n"; }
template<class T> inline void print_2vec(const std::vector<std::vector<T>> &v) { for (int i = 0; i < v.size(); ++i) { for (int j = 0; j < v[0].size(); ++j) { if (j != 0) { std::cout << " "; } std::cout << std::setw(13) << std::left << v[i][j]; } std::cout << "\n";}}
template<class T> inline bool inside(T y, T x, T H, T W) {return 0 <= y and y < H and 0 <= x and x < W; }
template<class T> inline double euclidean_distance(T y1, T x1, T y2, T x2) { return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); }
template<class T> inline double manhattan_distance(T y1, T x1, T y2, T x2) { return abs(x1 - x2) + abs(y1 - y2); }
template<typename T> T &chmin(T &a, const T &b) { return a = std::min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = std::max(a, b); }
template<class T> inline std::vector<T> unique(std::vector<T> v) { sort(v.begin(), v.end()); v.erase(unique(v.begin(), v.end()), v.end()); return v; }
// 初項s, 交差dのn個の数列の和
long long sum_of_arithmetic_progression(long long s, long long d, long long n) { return n * (2 * s + (n - 1) * d) / 2; }

const int INF = 1 << 30;
const double EPS = 1e-9;
const std::string YES = "YES", Yes = "Yes", NO = "NO", No = "No";
const std::vector<int> dy4 = {0, -1, 0, 1}, dx4 = {1, 0, -1, 0};
const std::vector<int> dy8 = { 0, -1, 0, 1, 1, -1, -1, 1 }, dx8 = { 1, 0, -1, 0, 1, 1, -1, -1 };

using namespace std;



int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	int L;
	cin >> L;
	V<int> A(L);
	FOR(i, 0, L) {
	    cin >> A[i];
	}

	VV<int> dp(5, V<int>(L + 1, INF));
	dp[0][0] = dp[1][0] = dp[2][0] = dp[3][0] = dp[4][0] = 0;

	FOR(i, 0, L) {
	    // 0, e, o, e, 0
	    FOR(j, 0, 5) {
	        V<int> cost(5, INF);
            cost[0] = cost[4] = A[i];

            // 偶数
	        FOR(k, max(2, A[i] - 3), A[i] + 5) {
	            if (k % 2 == 0) {
                    chmin(cost[1], abs(k - A[i]));
                    chmin(cost[3], abs(k - A[i]));
                }
            }

            // 奇数
            FOR(k, max(1, A[i] - 3), A[i] + 5) {
                if (k % 2 == 1) {
                    chmin(cost[2], abs(k - A[i]));
                }
            }

	        // not change
	        chmin(dp[j][i + 1], dp[j][i] + cost[j]);

	        // change mode
	        FOR(k, 1, 5) {
	            if (j + k <= 4) {
                    chmin(dp[j + k][i + 1], dp[j][i] + cost[j + k]);
                }
            }
	    }
	}

	int ans = INT_MAX;
	FOR(j, 0, 5) {
	    chmin(ans, dp[j][L]);
	}
	print(ans);

	return 0;
}

Measured memory_bytes: 5760