the temperature dropped 18 degrees F between 6 am and 6 pm. during the night the temperature fell another 8 degree F. at 6 am the temperature started rising. It rose 1degree F the first hour, 2 degree F the second hour, and 4 degree the third hour. The temperature rose another 5 degree F during the day. At 4pm the tempersture climbed to 31degree F. What was the temperature at 6 am the first day?