using System;

class Triangle
{
	public struct NeverCreateMe {}
	
    public Triangle(double side1, double side2, double side3)
    {
    	Console.WriteLine("3 sides");
    }

    public Triangle(double side1, double side2, NeverCreateMe ignored = default(NeverCreateMe), double angle = 0)
    {
    	Console.WriteLine("2 sides and 1 angle");
    }
    
    public Triangle(double side1, NeverCreateMe ignored = default(NeverCreateMe), double angle1 = 0, double angle2 = 0)
    {
    	Console.WriteLine("1 side and 2 angles");
    }
}

public class Test
{
	public static void Main()
	{
		var a = new Triangle(1.0, 2.0, 3.0);
		var b = new Triangle(1.0, 2.0, angle: 3.0);
		var c = new Triangle(1.0, angle1: 2.0, angle2: 3.0);
	}
}