Problems from Caesar's method

Code the following message YOU FORGOT YOUR KEYS by means of Caesar's method with key $$18$$.

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Development:

We represent in a table the new alphabet:

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
S T U V W X Y Z A B C D E F G H I J K L M N O P Q R

We replace every letter of the original message with its correspondent in the new alphabet:

Y O U F O R G O T Y O U R K E Y S
Q G M X G J Y G L Q G M J C W Q K

Solution:

The coded message will be: QGMXGJYGLQGMJCWQK.

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