a	b
1	a
2	b
3	c
4	d
5	f
6	e
a	b
1	a
2	b
3	c
3	c
3	c
4	d
5	f
6	e
a	b
1	a
2	b
3	c
3	c
3	c
4	d
6	e
5	f
a	b
1	a
2	b
3	c
3	c
3	c
4	d
5	f
6	e
7	g
0	#
0	#
1	a
2	b
3	c
3	c
3	c
4	d
5	f
6	e
7	g
a	b
1	a
2	b
3	c
t1	b	count(*)
t1	a	1
t1	b	1
t1	c	2
t2	c	1
t2	d	1
t2	e	1
t2	f	1