def parse_directions(input_directions):
    """Parse input_directions for single tile from str to list of str."""
    directions = []
    index = 0
    while index != len(input_directions):
        left = input_directions[index:]
        if left.startswith('s') or left.startswith('n'):
            directions.append(left[:2])
            index += 2
        else:
            directions.append(left[0])
            index += 1
    return directions