#!/usr/bin/env python3
parity = {"NE": {"N": -1, "E": 1}, "SE": {"E": -1, "S": 1}, "SW": {"S": -1, "W": 1}, "NW": {"W": -1, "N": 1}}
X, Y = sorted("NESW".index(d[-1:]) * 90 + sum(parity[d[-2:]][c] * 45 / 2 ** i for i, c in enumerate(d[-2::-1]))
              for d in input().split())
print(min(Y - X, 360 + X - Y))