Score : $300$ points
Given is a string $S$ consisting of lowercase English letters. Find the maximum positive integer $K$ that satisfies the following condition:
Here $S_1S_2...S_K$ represents the concatenation of $S_1,S_2,...,S_K$ in this order.
Input is given from Standard Input in the following format:
Print the maximum positive integer $K$ that satisfies the condition.
We can, for example, divide $S$ into four strings