7
1
2
3
1
8
1
1
1
3
1
1
4
1
1
4
1
1
1
3
1
8
2
5
7
1
8
2
2
1
6
1
1
1
1
1
1
2
4
1
1
3
3
2
3
10
8
1
6
1
Polar Explorer