def main():
play_game(gcd)
def main():
play_game(progression)
def main():
game_engine.play_game(prime)
def main():
game_engine.play_game(even)
def main():
"""Program start."""
play_game(calc)
def main():
game_engine.play_game(progression)
def main():
"""Program start."""
play_game(even)
def main():
"""Program start."""
play_game(progression)
def main():
play_game(prime)
def main():
game_engine.play_game(gcd)
def main():
game_engine.play_game(calc)
def main():
play_game(even)
def main():
play_game(calc)
def main():
"""Program start."""
play_game(prime)
