public static void Main(){
int choice = int.Parse(Console.ReadLine());
Console.Write("Inches = ");
var inches = double.Parse(Console.ReadLine());
var centimeters = inches * 2.54;
Console.Write("Centimeters = ");
Console.WriteLine(centimeters);
case 2:Console.Write("C = ");
var C = double.Parse(Console.ReadLine());
case 3:Console.Write("Radian = ");
var radian = double.Parse(Console.ReadLine());
var gradusi = (radian * 180)/Math.PI;
Console.Write("Gradusi = ");
Console.WriteLine(gradusi);
case 4: Console.Write("Bgn = ");
var bgn = double.Parse(Console.ReadLine());