Saudi Electronic University Computer Programming Task Revision

I want to rewrite this code to become without copying and plagiarism, the same code but modification

this is the code :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp8
{
class Program

{
static int sum = 0, count = 0;

static bool flag = false;
static void Main(string[] args)
{

Console.Write(isDigitIncreasing(13));
}

public static bool isDigitIncreasing(int input_number)

{

int n = get_number_of_digit(input_number);

int sum = 0;

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

{

sum = sum * 10 + 1;

count = count + sum;

}

for (int i = 1; i <= 9; i++)

{

if ((input_number) == count * i)

{

flag = true;

break;

}

else

flag = false;

}

return flag;

}

public static int get_number_of_digit(int num)

{

int size = 0;

do

{

num = num / 10;

size++;

} while (num > 0);

return size;

}
}
}