/usr/share/syrthes/tests/cas_3disks3d/ is in syrthes-tests 4.3.0-dfsg1-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/syrthes/tests/cas_3disks3d/mesh/
/usr/share/syrthes/tests/cas_3disks3d/mesh/3disks.syr
/usr/share/syrthes/tests/cas_3disks3d/mesh/3disks.syr_desc
/usr/share/syrthes/tests/cas_3disks3d/syrthes/
/usr/share/syrthes/tests/cas_3disks3d/syrthes/3disks3d.syd
/usr/share/syrthes/tests/cas_3disks3d/syrthes/Makefile
/usr/share/syrthes/tests/cas_3disks3d/syrthes/syrthes.py
/usr/share/syrthes/tests/cas_3disks3d/syrthes/usr_examples/
/usr/share/syrthes/tests/cas_3disks3d/syrthes/usr_examples/user.c
/usr/share/syrthes/tests/cas_3disks3d/syrthes/usr_examples/user_cond.c
/usr/share/syrthes/tests/cas_3disks3d/syrthes/usr_examples/user_hmt.c
/usr/share/syrthes/tests/cas_3disks3d/syrthes/usr_examples/user_ray.c