ID,neversmoke,smoke,pastsmoke,gender
1,0,1,0,male
2,0,1,0,female
3,0,0,0,male
4,1,0,0,female
5,0,0,1,male
6,0,1,0,female
7,0,0,1,male
8,0,0,1,female
9,1,0,0,male
10,0,0,1,female