Discovery Co. ltd. builds a satellite using a new kind of an intelligent camera. The camera has special software to detect cities and roads from an image, and is also able to detect every region (which is a connected part of surface), bounded by a series of connected roads with no other region inside. Using this technology, the satellite is able to compress the picture before sending it. The compressed format of a picture is the city locations and its regions.
Discovery has launched the satellite, without testing the software completely. So, after a while, they received some buggy pictures which includes one more extra region: the outer region. The outer region is the region of the plane enclosing every other region (which has infinite area). Further analysis shows that all images sent have the following properties:
1.All cities, in the image, have at least two roads to the other cities.
2.There is a path connecting every pair of cities.
3.There is at most one road between each pair of cities.
4.Roads do not cross each other except at the cities.
The above Figure shows a sample image received (see sample input).
You are to write a program to read a buggy image and report the outer region.