# Upper triangular matrix
# 1 2 3  5
# 0 3 2  1
# 0 0 3 -2
# 0 0 0  4
4 4 10
0 0 1
0 1 2
0 2 3
0 3 5
1 1 3
1 2 2
1 3 1
2 2 3
2 3 -2
3 3 4
