def naacl_line(sen_no, l1_pos, l2_pos, alignment_type="S"):
    """
        :param sen_no: 0-indexed sentence number
        :param l1_pos: 0-indexed position in the L1
        :param l2_pos: 0-indexed position in the L2
        :param alignment_type: S or P for sure or probable
    """
    return f"{sen_no+1} {l1_pos+1} {l2_pos+1} {alignment_type}"