1init
2set check 1
3set checkfrozen 1
4add 1
5add 2
6add 3
7add 0
8add -1
9add -2
10add -3
11add 0
12freeze 1
13freeze 2
14solve
15add -1
16add 2
17add 0
18add -1
19add 2
20add 0
21melt 2
22solve
23melt 1
24add 1
25add 0
26solve
27reset
28