We defined pore region as empty space where lateral diffusion of water is restricted by the surrounding protein. To find such space, we solvated water and capped horizontal diffusion of water using MMFP at the top and the bottom of the lipid bilayer (Z = +20/-20). After that, we ran short Langevin dynamics at very high temperature, so that any other that are not confined by the protein will diffuse away, followed by removal of water molecules that are not bound by protein extent. Finally, some water may stay close to the protein exterior. That is the "individual comparison" step designed for.