col1	col2	col3	file_idx	join_idx
A	A	line1	0	0
A	A	line1	1	0
A	A	line1	2	0
A	A	line6	2	0
E	A	line5	0	1
E	A	line5	1	1
I	A	line9	0	2
I	A	line9	1	2
M	A	line13	0	3
M	A	line13	1	3
P	D	line3	2	4
Q	A	line17	0	5
Q	A	line17	1	5
S	C	line2	2	6
U	A	line21	0	7
U	A	line21	1	7
W	A	line23	0	8
W	A	line4	2	8
W	A	line7	2	8
Y	A	line25	0	9
Y	A	line25	1	9
Z	A	line22	0	10
Z	A	line24	0	10
Z	A	line26	0	10
Z	A	line26	1	10
Z	Z	line5	2	11

