Instructions

Decode this string using the Ruby REPL below for your next instructions. The string was encoded with a simple Caesar cipher and then base64 encoded.

YHt1dzKJgYR9QDJggYkyfneGOYUydXpzgHl3Moh3gId3TDJ2gXV9d4Qygod+fjJ1gYB8h4R7gHVBdneId36BgneEP4OHe4w=

Hint: "Строка была закодирована со смещением восемнадцати."