class Roboter(object):
    def __init__(self):
        self.x = 0
        self.y = 0
        self.r = 'S'

    def schritt(self):
        if self.r == 'O':
            self.x = self.x + 1
        elif self.r == 'S':
            self.y = self.y + 1
        elif self.r == 'W':
            self.x = self.x - 1
        elif self.r == 'N':
            self.y = self.y - 1

    def rechts(self):
        if self.r == 'O':
            self.r = 'S'
        elif self.r == 'S':
            self.r = 'W'
        elif self.r == 'W':
            self.r = 'N'
        elif self.r == 'N':
            self.r = 'O'

    def links(self):
        if self.r == 'O':
            self.r = 'N'
        elif self.r == 'N':
            self.r = 'W'
        elif self.r == 'W':
            self.r = 'S'
        elif self.r == 'S':
            self.r = 'O'