int a;
int b;
Console.Title = "第一堂课";
Console.WriteLine("请输入a的值,按回车");
Console.Write("a=");
a = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("请输入b的值,按回车");
Console.Write("b=");
b = int.Parse(Console.ReadLine());
Console.WriteLine("a+b="+(a + b));
Console.ReadKey();