SP2056 CERC07P - Rectangular Polygon

In this problem, we will help the Faculty of Civil Engineering. They need a software to analyze ground plans of buildings. Specifically, your task is to detect outlines of a building when all of its corners are given. You may assume that each building is a rectangular polygon with each of its sides being parallel either with X or Y axis. Therefore, each of its vertex angles is exactly either 90 or 270 degrees.

The input contains several buildings. The description of each building starts with a single positive integer N, the number of corners (polygon vertices), 1

For each building, output one line containing N characters without any whitespace between them. The characters should be uppercase letters that specify directions of individual walls (sides) when the building outline is followed. "N" stands for North (the positive direction of the Yaxis), "E" for East (the positive direction of the X axis), "W" for West, and "S" for South. The "walk" should start in the vertex that has been given first in the input and always proceed in the clockwise direction.