print("Hello")
Answer = 0

Total = 0


    
while Answer != -1:
    if Answer <-1:
        print("You cannot enter negative numbers other than -1")
        Answer = int(input("Enter Number. (enter -1 to exit) "))
    if Answer >=0:
        Total = Total+Answer
        Answer = int(input("Enter Number. (enter -1 to exit) "))
    
    
else:
    print("Your total is {0}".format(Total))
    print("Goodbye")