a=matrix([[1,1,1],[1,2,2],[1,2,3]])
l= a.echelon_form()
print (l[0,0]*l[1,1]*l[2,2])
b=matrix([[1,2,3],[2,2,3],[3,3,3]])
q=b.echelon_form()
print (q[0,0]*q[1,1]*q[2,2])