player_gamertag = input("Please enter your gamer tag: ")
awnser = input(f"So your gamer tag is {player_gamertag}? (yes/no) ") 

while awnser.lower() not in ['yes', 'no']:
    print("Sorry, I only accept 'yes' or 'no' as an answer.")
    awnser = input("Please enter 'yes' or 'no': ")

if awnser.lower() == 'yes':
    print("Great, then let's begin")
elif awnser.lower() == 'no':
    print("Oh, okay. Let's try again.")
    player_gamertag = input("Please enter your gamer tag: ")
else:
    print("Sorry, I only accept 'yes' or 'no' as an answer.")