5 of 6 deleted 2 characters in body

><>, 46 43 35 + 4 for  -s= = 39 bytes

0&l?!v:3%?\&:n1+$o!
+nf0.>&n; >l&:@

This is an implementation of xnor's algorithm in ><>.

It takes the input string on the stack (-s flag with the standard interpreter).

You can try it out on the online interpreter.