Higher Command Block

summon MinecartCommandBlock ~ ~1 ~ {Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:MinecartCommandBlock,Riding:{id:FallingSand,TileID:157,Time:1},Command:"setblock ~-2 ~-3 ~ 20"},Command:"setblock ~-2 ~-2 ~ 20"},Command:"setblock ~-2 ~-1 ~ 20"},Command:"setblock ~-3 ~-3 ~ 20"},Command:"setblock ~-3 ~-2 ~ 20"},Command:"setblock ~-3 ~-1 ~ 20"},Command:"setblock ~-4 ~-3 ~ 20"},Command:"setblock ~-4 ~-2 ~ 20"},Command:"setblock ~-4 ~-1 ~ 20"},Command:"setblock ~ ~-1 ~ 10 7"}