How many cubes are with two faces painted?

Number of cubes with two face painted from the top side (Which is a square of 3 x 3 = 9 cubes ) is 4.
Number of cubes with two face painted from the 2^nd from top side (Which has four edges and edge has 3 such cubes) is 4 x 3 = 12.
Number of such cubes from vertical edges is 4 x 1 = 4
Number of such cubes from bottom face is 4 x 1 = 4
Hence total such cubes is 4 + 12 + 4 + 4 = 24