青蛙跳井的故事

            int jing = 10;
            int a = 0;
            for (int v = 0; a < jing;v++ )
            {
                a += 3;
                  Console.WriteLine("上午" + a);
                a -=  2;
                   Console.WriteLine("下午" + a);
                   Console.WriteLine("------------");
                if (a >= 10)
                {
                    Console.WriteLine(v);
                }
            }
            Console.ReadLine();