able to do (something) standing on one's head
to be able to do something easily and quickly
The boy is good at fixing his bicycle. He can do it standing on his head.
two equal horizontal bands of white (top) and red with a large disk slightly to the hoist side of center - the top half of the disk is red, the bottom half is white; the design represents the sun reflecting off a field of ice; the colors are the same as those of the Danish flag and symbolize Greenland's links to the Kingdom of Denmark