delete duplicates

[Aurora_86]

Good evening,
I have a file in which each element is tripled, e.g. I have three identical overlapping arches (the same color, layer, etc). How can I delete duplicates? My express tool does not work

 

[GP.]

eliminated (overkill) is an autocad command.

 

[Aurora_86]

eliminated (overkill) is an autocad command.

Thank you.