After the successful infiltration of the Frog Lounge, the JCs are on watch! The nine JCs have recruited two more guards, so there are 11 total frogs keeping an eye on every possible spot. Frogs see an unlimited distance, but only in all four cardinal directions (north, south, east, west), and their line of sight is blocked by walls (black cells). In order to maximize efficiency, no frog is in line of sight of any other frog. Finally, some walls have a number on them, indicating how many frogs are orthogonally adjacent to that wall (diagonals don't count). (NB: If you're not sure about the rules, this is a standard logic puzzle type that you can look up called "akari".)

Once you figure out where each frog is, order the 11 frogs in standard reading order (left to right, top to bottom) and take differences between adjacent values.