Xiao Ming made a math test paper with 25 questions in total. It is stipulated that 2 points are given for a correct answer, 1 point is deducted for a wrong answer, and no points are given for unanswered questions. Xiao Ming has a total of 34 points, and it is known that the unanswered questions are odd-numbered, so how many questions he answered correctly.
小明做了一份数学试卷，共25题．规定答对一题得2分，答错一题扣1分，未答的题不得分，小明共得了34分，且知他未答的题目是奇数道，则他答对多少道题．
<result>18</result>