#Greeting
print("Hi, I am Marvin, your personal bot.")

#Ask the user for a command
command = input("How can I help? ")

#Check for addition command

if command == "add" or command == "plus" or command == "Add" or command == "Plus":
    print("let's add some numbers")
    input1 = input("Number 1> ")
    input2 = input("Number 2> ")
    number1 = int(input1)
    number2 = int(input2)
    result = number1 + number2
    output = str(result)
    print(input1 + " + " + input2 + " = " + output)

#Check for subtraction command

elif command == "subtract" or command == "take" or command == "Subtract" or command == "Take":
    print("let's subtract some numbers")
    input1 = input("Number 1> ")
    input2 = input("Number 2> ")
    number1 = int(input1)
    number2 = int(input2)
    result = number1 - number2
    output = str(result)
    print(input1 + " - " + input2 + " = " + output)

#Check for division command

elif command == "divide" or command == "Divide":
    print("let's divide some numbers")
    input1 = input("Number 1> ")
    input2 = input("Number 2> ")
    number1 = int(input1)
    number2 = int(input2)
    result = number1 / number2
    output = str(result)
    print(input1 + " / " + input2 + " = " + output)

#Check for multiply command

elif command == "multiply" or command == "Multiply" or command == "times" or command == "Times":
    print("let's multiply some numbers")
    input1 = input("Number 1> ")
    input2 = input("Number 2> ")
    number1 = int(input1)
    number2 = int(input2)
    result = number1 * number2
    output = str(result)
    print(input1 + " x " + input2 + " = " + output)


#Check for average command

elif command == "average" or command == "Average":
    print("let's work out an average")
    how_many = input("How many numbers would you like to average?> ")
    how_many = int(how_many)
    total = 0
    number_list=[]
    for number_count in range(how_many):
        number = input("Enter number " + str(number_count+1) + "> ")
        total = total + int(number)
        number_list.append(number)
    result = total / how_many
    print("here are the numbers you wanted to average")
    for item in number_list:
        print(item)
    print("the average of those numbers = " +str(result))

#Check for shopping list command

elif command == "shopping" or command == "Shopping":
    #Create a shopping list calculator with given number of items based on user input and display it on screen

    shopping =[]

    how_many = input("how many items of shopping do you have? ")
    how_many_items = int(how_many)

    for item in range(how_many_items):
        new_item = input("Enter item number " + str(item+1) + " in the shopping list > ")
        shopping.append(new_item)

    #Print out the items

    for item in shopping:
        print(item)

    print("You added " + how_many + " items to the list")

    print("now let's calculate how much that will cost you!")

    total_cost=0

    for item in shopping:
        item_cost=input("how much is the item " + item + " in £ ? >")
        total_cost=total_cost+float(item_cost)

    print("the total cost of your shopping is £" + str(total_cost))

#Error handling for unknown commands

else:
    print("Sorry, I don't understand")