1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
2
2
1
0
1
0
1
0
1
0
1
0
1
0
1
0