Vignere Cipher Decoder

Traditional Vignere cipher squares have the offset for A at 0 (i.e. the identity letter is A), but some other sources have the offset for A be 1 (i.e. the identity letter is Z).

Non-ASCII alphabetic characters in the key will be ignored, and only ASCII alphabetic characters will be encoded or decoded. Other characters can be in the text, but they will be passed through without modification.

Key
A Offset
Input

Output