116 人解决，129 人已尝试。
145 份提交通过，共有 210 份提交。
2.0 EMB 奖励。
单点时限: 2.0 sec
内存限制: 256 MB
This problem is strictly to acclimate teams to the contest environment. We strongly suggest you first finish this problem, and then attempt the more complex practice problem.
The input file will contain an unknown number of lines with at most 100 characters on each line. All the characters will be printable ASCII characters. Note that the input file will always exist, but may be empty.
The number of lines in the input file.
one and two three
3
116 人解决，129 人已尝试。
145 份提交通过，共有 210 份提交。
2.0 EMB 奖励。