Solution.cs

using System;
using System.Linq;

class Result
{
    public static int getTotalX(int[] a, int[] b)
    {
        var totalXs = 0;
        var maximumA = a.Max(); 
        var minimumB = b.Min(); 
        var counter = 1;
        var multipleOfMaxA = maximumA;

        while (multipleOfMaxA <= minimumB)
        {
            var factorOfAll = true;

            foreach (var item in a) 
            {
                if (multipleOfMaxA % item != 0)
                {
                    factorOfAll = false;
                    break;
                }
            }

            if (factorOfAll)
            {
                foreach (var item in b) 
                {
                    if (item % multipleOfMaxA != 0)
                    {
                        factorOfAll = false;
                        break;
                    }
                }
            }

            if (factorOfAll)
                totalXs++;

            counter++;
            multipleOfMaxA = maximumA * counter;
        }
        return totalXs;
    }

}

class Solution
{
    public static void Main(string[] args)
    {

        string[] firstMultipleInput = Console.ReadLine().TrimEnd().Split(' ');

        int n = Convert.ToInt32(firstMultipleInput[0]);

        int m = Convert.ToInt32(firstMultipleInput[1]);

        var arr = Console.ReadLine().TrimEnd().Split(' ').ToList().Select(arrTemp => Convert.ToInt32(arrTemp)).ToArray();

        var brr = Console.ReadLine().TrimEnd().Split(' ').ToList().Select(brrTemp => Convert.ToInt32(brrTemp)).ToArray();

        int total = Result.getTotalX(arr, brr);

        Console.WriteLine(total);
    }
}