12.4.29 Various Olympic problems

Condition: In Morse code, each letter is encrypted with a sequence of dots and dashes. For example, the letter A corresponds to the sequence (.-), the letter Ш: (- - . -), and the letter T: (-). Prove that the Latin alphabet (26 letters) can be encrypted using sequences consisting of no more than 4 dots and a dash, and for the Russian alphabet you will have to use five-term sequences of dots and dashes.