"""Solution 16.3.3 — Doubling a recipe

Chapter 16: Handling Failures — Everyday Programming

Bug type: Logical

The doubling work that should run only after a successful conversion is
placed in the try block; if cups * 2 or the print logic ever failed it
would be wrongly treated as an input error. The success-only computation
belongs in else, leaving only the risky conversion in try.

Exercise: ex_16_3_3.py
"""

try:
    cups = float(input("How many cups? "))
except ValueError:
    print("That was not a number.")
else:
    doubled = cups * 2
    print("You need", doubled, "cups.")