f => f0000000
                       ff => ff000000
                      fff => fff00000
                     ffff => ffff0000
                    fffff => fffff000
                   ffffff => ffffff00
                  fffffff => fffffff0
                 ffffffff => ffffffff
                fffffffff => fffffffff0000000
               ffffffffff => ffffffffff000000
              fffffffffff => fffffffffff00000
             ffffffffffff => ffffffffffff0000
            fffffffffffff => fffffffffffff000
           ffffffffffffff => ffffffffffffff00
          fffffffffffffff => fffffffffffffff0
         ffffffffffffffff => ffffffffffffffff
        fffffffffffffffff => fffffffffffffffff0000000
       ffffffffffffffffff => ffffffffffffffffff000000
      fffffffffffffffffff => fffffffffffffffffff00000
     ffffffffffffffffffff => ffffffffffffffffffff0000
    fffffffffffffffffffff => fffffffffffffffffffff000
   ffffffffffffffffffffff => ffffffffffffffffffffff00
  fffffffffffffffffffffff => fffffffffffffffffffffff0
 ffffffffffffffffffffffff => ffffffffffffffffffffffff