随机成绩查询

int  fenshu;
            string zuoye;
            Console.WriteLine("输入成绩：");
      
            fenshu =  Convert .ToInt32 ( Console.ReadLine());

if (fenshu <60)
            {
                Console.WriteLine("是否认真做作业,（是，否）");
                zuoye = Console.ReadLine();
                if (zuoye=="是" )
                {
                    fenshu = fenshu + 5;
                    if (fenshu >= 60)
                    {
                        Console.WriteLine("勉强及格");
                    }
                }
                    else
                    {
                        Console.WriteLine("不及格");
                    }
               
            }
            else
            {
                Console.WriteLine("恭喜你，及格了。");
            }
            Console.WriteLine("结束");