... All 3 open up manually and have shutters attached to all 3. Every morning they are opened by Muriel's mother. One morning, I woke up early and decided to open the windows for her. 1, then 2, then 3. I came back into the room a couple of minutes later and #1 was closed. I thought, ok, don't open #1. She doesn't like that one opened in the morning. So the next morning I opened #2 and #3 only. 1 hour later, 2 was closed and 1 and 3 were open. I thought. I thought hard. Then I had it. They were on rotation. So the next day I only opened 1 and 2 seeing as 3 hadn't had a day closed yet. Right? I came back and 1 and 2 were closed leaving 3 opened. Ok... 3 always stays open 1 and 2 are on rotation opened every other day. I woke up the next morning and thought...