On a standard keyboard, that's G sharp or A flat.
Could be an Etude. Étude Op. 10, No. 5 in G-flat major, also known as the Black Key Étude, is a solo piano work composed by Frédéric Chopin in 1830.
Most call them "sharps or flats"
C sharp/D flat, D sharp/E flat, F sharp/G flat, G sharp/A flat, A sharp/B flat
Go look up Jay Chou's "Piano Battle" from his 2006 film "The Secret" - when the second guy (the one who doesn't look like a meanie) starts his part of the first song (there should be a total of three...