000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000O000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000O0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000O000000000000000000000000000000000000000000000000000000O0000000
hỏi có bao nhiêu chữ o
0 có chữ o nào toàn số 0
tất cả là 4 chữ o