Six boxes of different ARTICLES–A, B, C, D, E and F - are to be placed in six display racks of a shop numbered 1-6. The lowermost rack in the rack is numbered 1, the rack above it, number 2 and so on till the topmost rack is numbered 6.

C and E should be displayed next to each other, but A should be at least four racks away from D. F is preferred to be kept between B and C but away from A by three racks. A cannot be displayed next to C for the reason of mixed-product identity. A has to be placed at the bottom most rack.

If the positions of box of soaps C and E are interchanged then how many soap boxes were placed above E?