[ Processes and Operations ]

In one step, you can replace any letter in any of these words with any other letter (for example, in one step, you can get the word ЗКНОЗА from the word ЗАНОЗА. What is the minimum number of steps needed to make all the words the same (nonsensical words are allowed)?

#
After all the letter replacements in each column, the letters should become the same. The number of replacements will be the smallest if the most frequent letter (any of them if there are several) is kept in each column. For example, in the first column, letters 3 or К can be kept, both requiring four replacements. The minimum number of replacements is $4+4+5+4+4+4=25$.

## Answer

25 steps.

## Problem