-define(HIGHEST_TARGET_SCI, 16#2100ffff).
-define(HIGHEST_TARGET_INT, 16#ffff000000000000000000000000000000000000000000000000000000000000).
-define(NONCE_BITS, 64).
-define(MAX_NONCE, 16#ffffffffffffffff).
-define(DIFFICULTY_INTEGER_FACTOR, 16#1000000).