[header] How to decode a caesar box code [title] Count the number of characters in the code. [step] Here we have 16: g t y o r j o t e o u i a b g t [title] Determine how many rows you can divide the letters into equally (find the square root of the number you found in step 1. [step] If the square root isn't a whole number, round up). 
We can put 16 into 4 rows of 4 (i.e. the square root of 16 is 4).