using System;

using System.Linq;

using System.Collections.Generic;

public class Program

{

    public static int Rows;

    public static int Cols;

    public static List<int[]> directions = new List<int[]>() 

    { 

        new int[] { 1, 0 },

        new int[] { -1, 0 },

        new int[] { 0, 1 },

        new int[] { 0, -1 }

    };

    public static Tuple<int, Queue<int[]>> InitializeGrid(int[][] grid)

    {

        int freshCount = 0;

        var q = new Queue<int[]>();

        // initialize at first moment

        for (int i = 0; i < Rows; i++)

        {

            for (int j = 0; j < Cols; j++)

            {

                if (grid[i][j] == 2)

                {

                    q.Enqueue(new int[] { i, j });

                }

                else if (grid[i][j] == 1)

                {

                    freshCount++;

                }

            }

        }

        return new Tuple<int, Queue<int[]>>(freshCount, q);

    }

    public static int GetShelfDaysForOranges(int[][] grid) 

    {

        Rows = grid.Length;

        Cols = grid[0].Length;

        var data = InitializeGrid(grid);

        int result = 0;

        int freshCount = data.Item1;

        Queue<int[]> q = data.Item2;

        var next = new Queue<int[]>();

        // edge case

        if (freshCount == 0) 

            return result;

        while (q.Any())

        {

            int[] curRotten = q.Dequeue();

            foreach (int[] dir in directions)

            {

                int x = curRotten[0] + dir[0];

                int y = curRotten[1] + dir[1];

                // ignore empty cells, already rotten oranges and wrong coords

                if (x < 0 || x >= Rows || y < 0 || y >= Cols || grid[x][y] == 0 || grid[x][y] == 2)

                    continue;

                grid[x][y] = 2;

                next.Enqueue(new int[] { x, y });

                freshCount--;

            }

            if (!q.Any())

            {

                q = next;

                next = new Queue<int[]>();

                result++;

            }

        }

        return freshCount == 0 ? result - 1 : -1;

    }

    public static void Main()

    {

        Console.WriteLine("UniLecs");

        // tests

        var oranges = new int[][] 

        {

            new int[] { 2, 1, 1 },

            new int[] { 1, 1, 0 },

            new int[] { 0, 1, 1 }

        };

        Console.WriteLine(GetShelfDaysForOranges(oranges)); // 4

        oranges = new int[][] 

        {

            new int[] { 2, 1, 1 },

            new int[] { 0, 1, 1 },

            new int[] { 1, 0, 1 }

        };

        Console.WriteLine(GetShelfDaysForOranges(oranges)); // -1

    }

}