Kolosss

a = [1 2 3 4 1 5 9; 5 6 7 8 2 6 10;
     9 10 11 12 3 7 11; 13 14 15 16 4 8 12;
     1 5 9 13 1 0 0; 2 6 10 14 0 1 0;
     3 7 11 15 0 0 1;]
md = median(a(:))
b = [1 2 3; 1 2 3]
a(1:2,1:3) = b;
disp(a);
k = find(a==md)
k = floor(k/7 +1)
a(:,k(1)) = [];
disp(a)