tìm chữ số 1
999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888888!888888888888888888888888888889999999999999999999999999999999999777777777777777777777777777777777777777777777755555555555555555555555555555%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%^^^^^^^^^^^^^^^^^^^^^^^^^&&&&&&&&&&&&&&&&&&&********************(((((((((((((((((((((((((((((((((@@@@@@@@@@@@@@@@@@@@@@@@@#######################################4444444444$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Ko có số 1 bn ơi số một là dấu !
Lí do:
Bấm Shifft + 1 = !