source: There are dozens puzzles to solve that open approximately 50 locked doors, all are needed to find a way off the island.
target: There are dozens of puzzles to solve. The puzzles open approximately 50 locked doors. Opening all the doors is needed to find a way off the island.
references: There are dozens of puzzles to solve. The puzzles open approximately 50 locked doors. Opening all the doors is needed to find a way off the island.