# Homework 21, challenge: Swap.
#
# Define def swap(a, b): that returns b, a (two values as a tuple).
# Then:
#   1. Declare two variables x and y with starting values.
#   2. Print "Before:" with the values.
#   3. Use multi-assignment to capture swap(x, y) back into x and y.
#   4. Print "After:" with the new values.
#
# Run with: python exercises/21/homework/04-swap.py

# Your code goes here: