RE2 RegEx - the same number at both sides of slash

I need to build RegEx expression to find strings which matches:

<anytext>N/N

where N is the same number at both sides of slash, no matter which value exactly N has (it can be 1, 2 or 3 digits long).

I mean it should match for example:

ABC 4/4
ABCDEF 101/101
ABCDEF 22/22

but shouldn't match:

ABC 1/4
ABCDEF 101/50
ABCDEF 21/22

Is it possible using RegEx? How can I do it? I've been trying for some time, but I can't achieve that.

EDIT: I've forgot to write: I'm using Analytics Edge, which is said to use Regular Expression Language - .NET Framework 4. But when I try to put something in RegEx field I get info it should follow RE2 syntax.