Use Gauss' Lemma to compute
I know how to start this question but just unsure how to finish it, my working is as follows:
where is the number of negative least residues of the integers
the set of least residues mod 37 is
Does that mean I have to check through all of the integers in that set ( ) to see if they have a negative least residue in the set ? Because that would take a VERY long time, is there a faster way?