Problems from Boxes method

CLE TSE NTL OAL GID UW ANN ROO

Can you decode this message using the boxes method knowing that the key word is COMPUTER?

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Development:

We create a table with $8$ columns (as many letters as the key has) and $5$ rows (the longest group of letters is $3$ letters, adding a line for the key and another one below for the numbers that indicate the order)

C	O	M	P	U	T	E	R
$1$	$4$	$3$	$5$	$8$	$7$	$2$	$6$
C	O	N	G	R	A	T	U
L	A	T	I	O	N	S	W
E	L	L	D	O	N	E

Solution:

The message says "congratulations well done".

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