#!/opt/local/bin/lua -- -- See ../README.md -- -- -- Run as: lua ch-1.lua < input-file -- for line in io . lines () do num = tonumber (line) out = 0 for i = 0, 7 do bit = math . floor ((num - (num % (2 ^ i))) / (2 ^ i)) % 2 if bit == 1 then if i % 2 == 1 then out = out + 2 ^ (i - 1) else out = out + 2 ^ (i + 1) end end end print (out) end