transcript:
[picture of claude chat:]
claude: Wednesday, Monday, and Friday all contain the letter "D" — and so does Sunday and Saturday if you count the "d" at the end... wait, let me list them all carefully:

• Mon_d_ay
• Wednes_d_ay
• Fri_d_ay
• Sun_d_ay
• Satur_d_ay

So five days of the week contain the letter "d": Monday, Wednesday, Friday, Sunday, and Saturday. Tuesday and Thursday are the only two that don't.