CF873F Forbidden Indices

You are given a string $ s $ consisting of $ n $ lowercase Latin letters. Some indices in this string are marked as forbidden. You want to find a string $ a $ such that the value of $ |a|·f(a) $ is maximum possible, where $ f(a) $ is the number of occurences of $ a $ in $ s $ such that these occurences end in non-forbidden indices. So, for example, if $ s $ is aaaa, $ a $ is aa and index $ 3 $ is forbidden, then $ f(a)=2 $ because there are three occurences of $ a $ in $ s $ (starting in indices $ 1 $ , $ 2 $ and $ 3 $ ), but one of them (starting in index $ 2 $ ) ends in a forbidden index. Calculate the maximum possible value of $ |a|·f(a) $ you can get.

The first line contains an integer number $ n $ ( $ 1

Print the maximum possible value of $ |a|·f(a) $ .