As any experienced programmer must know the famous problem of "Edit Distance", however this
problem is considered an “alternating chain” if you have alternately made case sensitive.
Example:
"AaAaAbB" "B" "a" "aBaCdEf"
Alternating chains are considered in our problem.
We only have one operation that is permitted in exchange for a lower or upper case Latin letter.
Given a string giving the minimum number of changes to be considered an alternating chain.
Input
A string with no spaces line containing only uppercase and lowercase letters, one for each line of
maximum length 10 ^ 3 until end of file
Output
For each line print the minimum number of changes to the chain is a "chain alternately"