hackercupai/hackercup huggingface dataset:
As an experienced boomerangist, you take great pride in your trusty boomerang,
and you'd like to be able to show it off! Unfortunately, it doesn't look quite
right yet...

Like all boomerangs, yours is symmetrical in shape, with two **N** millimetre-
long halves. However, what's not necessarily symmetrical is its paint job —
each millimetre-long section of each half has been painted some color. There
are 26 possible colors, represented by uppercase letters ("A" to "Z"), and the
**i**th section of the left half (counting from the left end) has color
**Ai**, while the **i**th section of the right half (counting from the right
end) has color **Bi**. You'd like your boomerang to be completely symmetrical
(which is the case when the **i**th section in the left half has the same
color as the **i**th section in the right half, for all 1 ≤ **i** ≤ **N**) as
soon as possible!

To that end, you're enlisting the help of your two best friends, Jack and
Jill, to repaint the left half of your boomerang until it matches the right
half. Every second, Jack may paint over a "prefix" of the left half with a
solid color, while Jill may simultaneously paint over a disjoint "suffix". In
other words, every second, Jack and Jill will each select a color (from "A" to
"Z"), Jack will select a value **x** (0 ≤ **x** ≤ **N**), and Jill will select
a value **y** (0 ≤ **y** ≤ **N - x**). Then, Jack will repaint the first **x**
sections of the left half of the boomerang with his color, while Jill will
repaint the last **y** sections of the left half of the boomerang with her
color. Painting over a section completely overwrites its previous color.

What's the minimum amount of time (in seconds) it can take Jack and Jill to
make your boomerang completely symmetrical?

### Input

Input begins with an integer **T**, the number of boomerangs you want to
decorate. For each boomerang, there is first a line containing the integer
**N**, then two lines that each contain a string of length **N**. The **i**th
character of the second line is **Ai**. The **i**th character of the third
line is **Bi**.

### Output

For the **i**th boomerang, print a line containing "Case #**i**: " followed by
the minimum number of seconds it will take Jack and Jill to make your
boomerang's paint job symmetrical.

### Constraints

1 ≤ **T** ≤ 75
1 ≤ **N** ≤ 100,000

### Explanation of Sample

The first boomerang is already symmetrical, so no work needs to be done. The
second boomerang can be made symmetrical in 1 second. Jack will cover the
first millimetre with 'C', and Jill will cover the third millimetre with 'A'.
The third boomerang takes 2 seconds to paint. One possible solution is for
Jack to paint the first two millimetres with 'A' and then the first millimetre
with 'B'.