P8153 "PMOI-5" Free Points Problem / Yet Another Easy Strings Merging

**This problem is collecting fake solutions and hack testdata. If you got AC with a fake solution, feel free to private message the setter with a hack.** > The information may be redundant. — command_block, "Pre-exam Tips" djy was reading P8001, misread the problem, got very upset, and then this problem was created.

You are given $n$ binary strings. Each time, you may remove one character from the beginning of some string, and append the **remaining string** to the end of a new string $S$. Maximize the number of adjacent equal-character pairs in $S$. For example, if you have two strings `1010 111`, and you remove the first character of the first string, then `010` is appended to $S$. **Strings can be reused.**

The first line contains a positive integer $n$, indicating the number of strings. The next $n$ lines each contain a binary string.

Output one integer in a single line, representing the answer.

[Sample Explanation] By removing the first character each time, the changes of $S$ are `100->10000->100000`, and the answer is $4$. [Constraints] Let $|s|$ be the length of string $s$, and $s_i$ be the $i$-th string. **This problem uses bundled tests.** - Subtask 1 (30 pts): $n,\sum|s_i|\le 11$. - Subtask 2 (30 pts): $n,\sum|s_i|\le 10^3$. - Subtask 3 (30 pts): $n,\sum|s_i|\le 10^5$. - Subtask 4 (10 pts): no additional constraints. For $100\%$ of the data, $1\le n\le 10^6$, $n\le \sum |s_i|\le 10^6$, and for all $i\in [1,n]$, $|s_i|\ge 1$. Translated by ChatGPT 5