Data from 4th test is here.
Minimal length of word is 9 symbols.
If we take the last 9 symbols from the Morse sequence, then we wouldn’t find any words with this ending.
So, we can’t make text… But the right answer is 57330892800.
How can this be?
What is a symbol for you ? a letter, a character ( . or - ) or a morse letter?
“symbol” is “.” or “-”
The last 9 symbols in the Morse sequence are “-.----…”. But there are no words with this ending.
We don’t have the same sequence. Mine is ending by “.–.-.-…”
OK, sorry 
You are right.
It’s my mistake.