A program that finds the largest area of equal neighbor elements in a rectangular matrix and prints its size

LargestAreaNeighbourElementsInMatrix

using System;

namespace Task_7_LargestAreaNeighbour
{
class Program
{
static void Main()
{
    //Ask for a size of the matrix
    Console.Write("Please enter the matrix size: ");
    string input = Console.ReadLine();
    int Size = 0;
    while (int.TryParse(input, out Size) == false)
    {
        Console.Write("Please enter a valid integer!: ");
        input = Console.ReadLine();
    }
    //Declare matrix
    int[,] Matrix = new int[Size, Size];
    //Declare all variables:
    int CurrentRepeats = 0;
    int MaxRepeats = 0;
    int StartRow = 0;
    int StartCol = 0;
    int RepeatedDigit = 0;
    int CurrentRow = 0;
    int CurrentCol = 0;
    Random RandomDigit = new Random();
    //Fill the matrix with random digits (1-9)
    FillMatrixRandom(Size, Matrix, RandomDigit);
    //Print the matrix
    PrintMatrix(Size, Matrix);
    //Put the whole code in 2 integrated for loops for (rows) ... for (cols)
    for (StartRow = 0; StartRow < Size; StartRow++)
    {
        for (StartCol = 0; StartCol < Size; StartCol++)
        {
            //Check for OutOfRangeExceptions
            if ((StartCol+1) < Size)
            {
                //Start (0;0) and look for equal neighbour elements to the right side
                //If you find equal elements, continue searching to the right side, until you find a different one
                while (Matrix[StartRow,StartCol] == Matrix[StartRow, StartCol+1])
                {
                    //Save the start position of the first element, so you can go back there
                    //Save the repeated element
                    //Count all found equal elements   
                }
            }
            //Check for OutOfRangeExceptions
            if ((StartRow+1) < Size)
            {
                //Go back on start positon and look for equal neighbour elements down side
                //If you find equal elements down side, continue searching until you find a different one
                while (Matrix[StartRow,StartCol] == Matrix[StartRow+1, StartCol])
                {
                    //Save the start position of the first element, so you can go back there.
                    //Save the repeated element
                    //Count all found equal elements      
                }
            }
            //If no equal elements found reloop and go to next element in the matrix
        }
    }

    //Print the result -> MaxRepeats, RepeatedDigit
}

private static void FillMatrixRandom(int Size, int[,] Matrix, Random RandomDigit)
{
    for (int row = 0; row < Size; row++)
    {
        for (int col = 0; col < Size; col++)
        {
            Matrix[row, col] = RandomDigit.Next(1, 9);
        }
    }
}

private static void PrintMatrix(int Size, int[,] Matrix)
{
    Console.WriteLine();
    for (int row = 0; row < Size; row++)
    {
        for (int col = 0; col < Size; col++)
        {
            Console.Write("{0,3}", Matrix[row, col]);
        }
        Console.WriteLine();
    }
    Console.WriteLine();
}
}
}