Sierpinskified Code

Write a rectangular block of text that when arranged into a Sierpinski carpet, using same-sized blocks of spaces for the empty portions, creates a program that outputs the iteration number of the carpet.

For example, if your text block is

TXT
BLK

then running the program

TXTTXTTXT
BLKBLKBLK
TXT   TXT
BLK   BLK
TXTTXTTXT
BLKBLKBLK

should output 1 because the shape of the program represents the first iteration of the Sierpinski carpet.

Similarly, running

TXTTXTTXTTXTTXTTXTTXTTXTTXT
BLKBLKBLKBLKBLKBLKBLKBLKBLK
TXT   TXTTXT   TXTTXT   TXT
BLK   BLKBLK   BLKBLK   BLK
TXTTXTTXTTXTTXTTXTTXTTXTTXT
BLKBLKBLKBLKBLKBLKBLKBLKBLK
TXTTXTTXT         TXTTXTTXT
BLKBLKBLK         BLKBLKBLK
TXT   TXT         TXT   TXT
BLK   BLK         BLK   BLK
TXTTXTTXT         TXTTXTTXT
BLKBLKBLK         BLKBLKBLK
TXTTXTTXTTXTTXTTXTTXTTXTTXT
BLKBLKBLKBLKBLKBLKBLKBLKBLK
TXT   TXTTXT   TXTTXT   TXT
BLK   BLKBLK   BLKBLK   BLK
TXTTXTTXTTXTTXTTXTTXTTXTTXT
BLKBLKBLKBLKBLKBLKBLKBLKBLK

should output 2 because this is the shape of the second Sierpinski carpet iteration.

Running the text block as is

TXT
BLK

should output 0 because it can be considered the zeroth iteration.

This should work for all further iterations. (Stopping at a reasonable maximum like 232 or 231-1 is fine.)

#Details

You can use this stack snippet to generate a carpet for a given text block at any iteration:

<script>function c(e){e=e.split("\n");for(var n=new Array(3*e.length),t=0;t<n.length;t++){var l=t%e.length;n[t]=e[l]+(t>=e.length&&t<2*e.length?e[l].replace(/./g," "):e[l])+e[l]}return n.join("\n")}function f(){for(i=document.getElementById("i").value,n=parseInt(document.getElementById("n").value);n>0;)i=c(i),n--;document.getElementById("o").value=i}</script><textarea id='i'placeholder='code block...'rows='8'cols='32'></textarea><br>Iterations <input id='n'type='text' value='1'><br><br><button type='button'onclick='f()'>Generate</button><br><br><textarea id='o'placeholder='output...'rows='8'cols='32'style='background-color:#eee'readonly></textarea>

#Scoring

The submission whose initial text block is smallest by area (width times height) is the winner. The TXT\nBLK example is 3 by 2 for a score of 6. (Basically the shortest code wins, hence the code-golf tag.)

Tiebreaker goes to the submission that uses the fewest distinct characters in their text block.