50 50
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
4
1
3
5
1
5
2
5
1
3
3
6
5
2
6
3
6
5
2
4
5
5
3
4
6
1
5
1
5
2
1
4
3
5
4
3
5
2
2
6
6
4
2
3
1
3
1
4
6