Alice: https://www.youtube.com/watch?v=UYU8Q3
Bob: https://www.youtube.com/watch?v=QQUYUBQ5XAU3Q1XAU3Q5
Alice: https://www.youtube.com/watch?v=U1UBUEXAQQU8XAU4U8U8Q5
Bob: https://www.youtube.com/watch?v=5E57
Bob: https://www.youtube.com/watch?v=53XAU5U7UEQ5XAUGUEU7QQXAQ3U7Q8
