Command Block Building 1

setblock ~ ~-1 ~ command_block 0 replace {Command:/setblock ~ ~ ~-1 command_block 0 replace {Command:/setblock ~1 ~ ~ command_block 0 replace {Command:/setblock ~ ~ ~1 command_block 0 replace {Command:/setblock ~ ~1 ~ command_block 0 replace {Command:/say Finished!}}}}}

http://i.imgur.com/xQfidZt.png