EuclideanAlgorithm

using System;
// Write a program that calculates the greatest common divisor (GCD) of given two numbers. Use the Euclidean algorithm (find it in Internet).

class GreatestDivisor
{
    static void Main()
    {
        int firstNum = int.Parse(Console.ReadLine());
        int secNum = int.Parse(Console.ReadLine());

        int devider = 0;
        int remainder = 0;
        int saver = 0;//save secNum value

        while (true)
        {
            devider = firstNum / secNum;
            remainder = devider * secNum;
            saver = secNum;
            secNum = firstNum - remainder;
            firstNum = saver;

            if (secNum == 0)
            {
                Console.WriteLine(saver);
                break;
            }
        }
    }
}