/summon MinecartCommandBlock ~ ~1 ~ {Command:/setblock ~ ~-4 ~ redstone_block,Riding:{id:MinecartCommandBlock,Command:"/tp @e[type=ArmorStand,name=C] ~ ~5 ~",Riding:{id:MinecartCommandBlock,Command:"/tp @e[type=ArmorStand,name=C] @e[type=ArmorStand,name=B]",Riding:{id:MinecartCommandBlock,Command:"/execute @e[type=ArmorStand,name=A] ~ ~ ~ /summon ArmorStand ~ ~ ~ {CustomName:C,CustomNameVisible:1,NoGravity:1,Equipment:[{id:stone,Count:1},{},{},{},{}]}",Riding:{id:MinecartCommandBlock,Command:"/summon ArmorStand ~-5 ~ ~ {CustomName:B,CustomNameVisible:1,NoGravity:1}",Riding:{id:MinecartCommandBlock,Command:"/summon ArmorStand ~5 ~ ~ {CustomName:A,CustomNameVisible:1,NoGravity:1}",Riding:{id:MinecartCommandBlock,Command:/fill ~ ~2 ~ ~ ~2 ~ redstone_block,Riding:{id:MinecartCommandBlock,Command:/setblock ~ ~1 ~ command_block 0 replace {Command:/fill ~ ~1 ~ ~ ~1 ~ stone 0 replace redstone_block},Riding:{id:MinecartCommandBlock,Command:/setblock ~ ~3 ~ command_block 0 replace {Command:/fill ~ ~-1 ~ ~ ~-1 ~ redstone_block 0 replace stone},Riding:{id:MinecartCommandBlock,Command:/setblock ~-1 ~2 ~ command_block 0 replace {Command:"/tp @e[type=ArmorStand,name=C] ~0.1 ~ ~"},Riding:{id:MinecartCommandBlock,Command:/setblock ~1 ~2 ~ command_block 0 replace {Command:"/execute @e[type=ArmorStand,name=C] ~ ~ ~ /summon ArmorStand ~ ~ ~ {CustomName:Here_is_C,CustomNameVisible:1,NoGravity:1}"},Riding:{id:MinecartCommandBlock,Command:/setblock ~ ~2 ~-1 command_block 0 replace {Command:"/execute @e[type=ArmorStand,name=B] ~ ~ ~ /tp @e[type=ArmorStand,name=C,rm=20] @e[type=ArmorStand,name=B,c=1]"},Riding:{id:MinecartCommandBlock,Command:/setblock ~ ~2 ~1 command_block 0 replace {Command:"/kill @e[type=ArmorStand,name=Here_is_C]"},Riding:{id:MinecartCommandBlock,Riding:{id:FallingSand,Time:1,Block:activator_rail,Riding:{id:FallingSand,Time:1,Block:redstone_block,Riding:{id:FallingSand,Time:1,Block:stone,Riding:{id:FallingSand,Time:1,Block:command_block,TileEntityData:{Command:/fill ~ ~-2 ~ ~ ~3 ~ air},Riding:{id:FallingSand,Time:1,Block:stone,Riding:{id:FallingSand,Time:1,Block:command_block,TileEntityData:{Command:/kill @e[type=MinecartCommandBlock,dy=6]}}}}}}}}}}}}}}}}}}}}}