4
1 0 1
3 1 1
2 1 2
3 0 2
2 1 1
3 1 2
2 1 2
0 1 3
2 0 3
0 2 3
3 0 2
3 0 3
1 2 2
1 3 0
0 2 0
1 0 1
3 0 2
3 2 -1
1 0 3
2 1 -1
0 0 0