avilable_foods=["soup","beaf","noddle","pepper"]

 request_foods=["soup","rice","beaf","suggar"]

 for request_food in request_foods:

     if request_food in avilable_foods:

         print("adding "+request_food+".")

     else:

         print("sorry,we don't support for "+request_food+".")

 print("finish your food.")

 print("\n")

 customer_list=["lin","kakaxi","daitu","admin","sasik"]

 customer_list=[]

 if customer_list:

     for customer in customer_list:

         if customer =="admin":

             print("hello admin,welcome!")

         else:

             print("hello,"+customer+" thank you for logging")

 else:

     print("we need to find some users.")

 current_users=["jack","wang","robot","li","mole"]

 new_users=["zhao","mile","JACK","robot"]

 for new_user in new_users:

     if new_user.lower() in current_users:

         print("the name "+new_user+" is current occpuied")

     else:

         print("welcome to github!")

 print("\n")

 nums = [1,2,3,4,5,6,7,8,9]

 for num  in nums:

     if num == 1:

         print("1st")

     elif num == 2:

         print("2nd")

     elif num == 3:

         print("3rd")

     else:

         print(str(num)+"th")