## Multiply two matrices.

## A is 3x3 matrix
A = [[1, 2, 3],
     [4, 5, 6],
     [7, 8, 9]]
     
## B is 3x4 matrix.     
B = [[4, 6, 3, 2],
     [8, 7, 0, 2],
     [6, 0, 9, 4]]
     
## Result is 3x4 matrix.
R = [[0,0,0,0],
     [0,0,0,0],
     [0,0,0,0]]

## Iterate through rows of A.
for i in 0..(A.length)
  ## Iterate through columns of B.
  for j in 0..(B[0].length)
    for k in 0..(B.length)
        R[i][j] += A[i][k] * B[k][j]
    end
  end
end

for row in R
  print(row)
end