Quration $2$

Max score $20\mathrm{.}00$

Minimire the cost

You are given two strings $5$ and $R,$ each of sire $N$ containing lowercase English leners.

You can do the following operations any number of times

Type $0$: Select any two indices$/$and$/$hom $0$ to $n.$ I and swap S$4$ with $5$ III This operalion is free of cost

Type i Seled any inder thom O lo n $-$ Iand swap Syy with any lowercave English lener. This operation costs $f$ coin

Task

Defermine the minimum cost to maler string $5$ equal to $R$

Note Obased indeaing is folluwed

Esample

Answiygotans

$-N=S$

$-S=$ abotar'