text: class Dinglemouse(object):
      
      def __init__(self):
          self.name = None
          self.sex  = None
          self.age  = None
          self.index=0
      def setAge(self, age):
          if not self.age:
              self.age = [age, self.index] 
          else: 
              self.age[0]=age;
          self.index+=1
          return self
          
      def setSex(self, sex):
          if not self.sex:
              self.sex = [sex, self.index]
          else: 
              self.sex[0]=sex;
          self.index+=1
          return self
          
      def setName(self, name):
          if not self.name:
              self.name = [name, self.index]
          else: 
              self.name[0]=name;
          self.index+=1
          return self
          
      def hello(self):
          res=[item for item, extra in sorted([i for i in [self.name, self.age, self.sex] if i], key=lambda x:(x[1]))]
          str=["Hello."]
          for i in res:
              if self.name and i==self.name[0]:
                  str.append(f"My name is {self.name[0]}.")
              elif self.sex and i==self.sex[0]:
                  str.append("I am male.") if i =="M" else str.append("I am female.")
              elif self.age and i==self.age[0]:
                  str.append(f"I am {self.age[0]}.")
          return " ".join(str)