class board:
        def __init__(self, size):
                self.size = size
                self.board = []
		self.stonelist = []
                tempvector = []
                for i in range(size):
                        tempvector.append(0)
                for i in range(size):
                        self.board.append(eval(repr(tempvector)))

        def returnpoint(self, x, y):
                return self.board[y][x]

        def setpoint(self, x, y, new):
		if (new == 1 or new == -1) and (self.returnpoint(x,y) == 0):
			self.stonelist.append([x,y])
		if new == 0 and self.returnpoint(x,y) != 0:
			self.stonelist.remove([x,y])
                self.board[y][x]=new

	def removestones(self, coordlist): #removes a group from the board
		for i in range(len(coordlist)):
			self.setpoint(coordlist[i][0], coordlist[i][1], 0)

        def __repr__(self):
                string = ""
                for i in range(self.size):
                        string += '%s = %s\n' % (i+1, self.board[i])
                return string