Last Letter : S
From PASTS - 2
the middle S cant be there coz of DISCO - 0
So its PA, PT, PS, AT, AS, TS
PA, PT, AT, AS not possible coz
PARTY - 1
BATHS - 1
So either PS or AS
So S there anyway.
Next Guess: PEARS...if 1..then second last letter is T.