1111111111111111111111111111111111111111111111111111111111111111111+99999999999999999999999999999999999+22222222222222222222222222222222+77777777x0x999999999999999x1111111+444444444444444444444444444x99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999
xem hết rồi giải
= báo cáo:>>>
= b-=u-=o-=i-=báo cáo