C
caothaituan


bai nay hay lam cuc ki buc xuc>>>>>>>&g
de bai :
rut gon day so sau:
2! +2!3! +3!4! + 4!5! + 5!6! -1!2!3!4!5!
X( X( X(
X( :-/ :-/ :-/ :-/ :-/
de bai :
rut gon day so sau:
2! +2!3! +3!4! + 4!5! + 5!6! -1!2!3!4!5!
X( X( X(