output_description: Print `Yes` if it is possible to set each day's travel distance so that he
  will be back at home at the end of Day N. Otherwise, print `No`.
  
  * * *
input_description: The input is given from Standard Input in the following format:
  
      
      
      S
attempt: a = set(list(input()))
  print("Yes" if ~("N" in a ^ "S" in a) and ~("W" in a ^ "E" in a) else "No")
  
problem_description: Statement
  
  Snuke lives on an infinite two-dimensional plane. He is going on an N-day
  trip. At the beginning of Day 1, he is at home. His plan is described in a
  string S of length N. On Day i(1 ≦ i ≦ N), he will travel a positive distance
  in the following direction:
  
    * North if the i-th letter of S is `N`
    * West if the i-th letter of S is `W`
    * South if the i-th letter of S is `S`
    * East if the i-th letter of S is `E`
  
  He has not decided each day's travel distance. Determine whether it is
  possible to set each day's travel distance so that he will be back at home at
  the end of Day N.
samples: [{"input": "SENW", "output": "Yes\n    \n\nIf Snuke travels a distance of 1 on each day, he will be back at home at the\nend of day 4.\n\n* * *"}, {"input": "NSNNSNSN", "output": "Yes\n    \n\n* * *"}, {"input": "NNEW", "output": "No\n    \n\n* * *"}, {"input": "W", "output": "No"}]