a
0
2
a
0
1
a
0
2
a
0
1
a
0
2
a
0
1
a
0
1
a
0
1
a
0
1
a
0
1
a
0
1
a
0
2
a
0
1
a
0
1
a
0
1
a
0
1
a
0
1
a
0
3
a
0
1
a
0
1
a
0
1
a
0
1
a
0
1
a
0
1