Answer:
Written in Python:
def myfunction():
userinput = input("User input: ")
while(userinput != "end"):
countdown(userinput)
userinput = input("User input: ")
Step-by-step explanation:
This line defines the function
def myfunction():
This line prompts user for user input
userinput = input("User input: ")
The following while loop checks if userinput is not "end". It continues execution until user input "end"
while(userinput != "end"):
countdown(userinput) If yes, the input is passed to the countdown function for execution
This line prompts user for another user input
userinput = input("User input: ")
Please note the above code segment assumes that countdown() function has already been written and defined