1 2 0 0
0 3 9 0
0 1 4 0

##</code><code>##

M = 10^7
N = 10^2

##</code><code>##

A  = [ 1 2 3 9 1 4 ]
IA = [ 1 3 5 7 ]
JA = [ 1 2 2 3 2 3 ]