Задача 74: Несократимая дробь

EulerFunc.cs

using System;
					
public class Program
{
	public static int EulerFunc(int n)
	{
		if (n <= 0)
		{
			throw new Exception("N should be greater than 0!");
		}
		
		int result = n;
		for (int i = 2; i * i <= n; i++)
		{
			if (n % i == 0)
			{
				result -= result / i;
			}                    
			
			while (n % i == 0)
			{
				n /= i;
			}
		}
		
		if (n > 1)
		{
			result -= result / n;
		}
		
		return result;
	}	
	
	public static void Main()
	{
    		Console.WriteLine("UniLecs");
		Console.WriteLine(string.Format("Answer = {0}", EulerFunc(11))); // 10
		Console.WriteLine(string.Format("Answer = {0}", EulerFunc(12))); // 4
		Console.WriteLine(string.Format("Answer = {0}", EulerFunc(17))); // 16
	}
}