/usr/share/man/man1/x86_64-linux-gnu-cpp-5.1.gz is in cpp-5 5.4.0-6ubuntu1~16.04.10.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/man/man1/cpp-5.1.gz
/usr/share/man/man1/cpp-5.1.gz