Greatest Common Divisor

 Introduction
 The greatest common divisor of two positive integers is the highest number that can divide those two other numbers. The following code shows how to find the greatest common divisor of two numbers:
```using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Arithmetic
{
public static class Exercise
{
public static int GreatestCommonDivisor(int a, int b)
{
int remainder;

while (b != 0)
{
remainder = a % b;
a = b;
b = remainder;
}

return a;
}
}

public class Program
{
static int Main(string[] args)
{
int x, y;

Console.WriteLine("This program allows calculating the " +
"greatest common divisor");
Console.Write("Enter Value 1: ");
x = int.Parse(Console.ReadLine());
Console.Write("Enter Value 2: ");
y = int.Parse(Console.ReadLine());

Console.WriteLine("\nThe Greatest Common Divisor of {0} and {1} is {2}.",
x, y, Arithmetic.GreatestCommonDivisor(x, y));

return 0;
}
}
}```

Here is an example of running the program:

```This program allows calculating
the greatest common divisor
Enter Value 1: 15
Enter Value 2: 3

The Greatest Common Divisor of 15 and 3 is 3.
Press any key to continue . . .```

Here is another example of running the program:

```This program allows calculating
the greatest common divisor
Enter Value 1: 64
Enter Value 2: 12

The Greatest Common Divisor of 64 and 12 is 4.
Press any key to continue . . .```

Here is one more example of running the program:

```This program allows calculating the greatest common divisor
Enter Value 1: 48024
Enter Value 2: 128

The Greatest Common Divisor of 48024 and 128 is 8.
Press any key to continue . . .```