using System;

public class Program
{
    private int L;
    private int[] A;

    public void Solve()
    {
        var sc = new Scanner();
        L = sc.NextInt();
        A = new int[L];
        for (int i = 0; i < L; i++)
        {
            A[i] = sc.NextInt();
        }


        var dp = new long[L + 1, 5];

        for (int i = 0; i < L; i++)
        {
            long min = long.MaxValue;

            for (int j = 0; j <= 4; j++)
            {
                min = Math.Min(min, dp[i, j]);
                long plus = -1;
                switch (j)
                {
                    case 0:
                    case 4:
                        plus = A[i];
                        break;
                    case 1:
                    case 3:
                        plus = A[i] == 0 ? 2 : A[i] % 2;
                        break;
                    case 2:
                        plus = (A[i] + 1) % 2;
                        break;
                }

                dp[i + 1, j] = min + plus;
            }
        }

        long ans = long.MaxValue;
        for (int i = 0; i <= 4; i++)
        {
            ans = Math.Min(ans, dp[L, i]);
        }

        Console.WriteLine(ans);
    }


    public static void Main(string[] args)
    {
        new Program().Solve();
    }
}

class Scanner
{
    public Scanner()
    {
        _pos = 0;
        _line = new string[0];
    }

    const char Separator = ' ';
    private int _pos;
    private string[] _line;

    #region スペース区切りで取得

    public string Next()
    {
        if (_pos >= _line.Length)
        {
            _line = Console.ReadLine().Split(Separator);
            _pos = 0;
        }

        return _line[_pos++];
    }

    public int NextInt()
    {
        return int.Parse(Next());
    }

    public long NextLong()
    {
        return long.Parse(Next());
    }

    public double NextDouble()
    {
        return double.Parse(Next());
    }

    #endregion

    #region 型変換

    private int[] ToIntArray(string[] array)
    {
        var result = new int[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = int.Parse(array[i]);
        }

        return result;
    }

    private long[] ToLongArray(string[] array)
    {
        var result = new long[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = long.Parse(array[i]);
        }

        return result;
    }

    private double[] ToDoubleArray(string[] array)
    {
        var result = new double[array.Length];
        for (int i = 0; i < array.Length; i++)
        {
            result[i] = double.Parse(array[i]);
        }

        return result;
    }

    #endregion

    #region 配列取得

    public string[] Array()
    {
        if (_pos >= _line.Length)
            _line = Console.ReadLine().Split(Separator);

        _pos = _line.Length;
        return _line;
    }

    public int[] IntArray()
    {
        return ToIntArray(Array());
    }

    public long[] LongArray()
    {
        return ToLongArray(Array());
    }

    public double[] DoubleArray()
    {
        return ToDoubleArray(Array());
    }

    #endregion
}

Measured memory_bytes: 23624