N = 5;
M = 6;
R = 3;
C = 3;
a = [|6,10,9,8,5,7,
     |7,1,6,5,8,8,
     |7,6,6,1,5,2,
     |1,5,1,10,8,4,
     |4,10,8,9,9,8|];