you have 16 Cameras

For each camera you would have to store 16 bits for figuring on which monitor the camera is visible on.

Camera   Monitor bits          1 1 1 1 1
  No.    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5

  0      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  1      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  2      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  3      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  4      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  5      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  6      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
  7      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  8      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
  9      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 10      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 11      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 12      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
 13      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 14      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 15      0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Could you use 16 "Camera keys" to select the camera and 16 "monitor" keys to switch that monitor to that camera if they are pressed at the same time ?