public static void Main()
Console.WriteLine("Type first number...");
int firstnum = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Select Operation *,/,+,-");
string sum = Console.ReadLine();
Console.WriteLine("Type second number...");
int secondnum = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Answer: {0}",firstnum+secondnum);
Console.WriteLine("Answer: {0}",firstnum-secondnum);
Console.WriteLine("Answer: {0}",firstnum*secondnum);
Console.WriteLine("Answer: {0}",firstnum/secondnum);