program fuckyoupentuple;
var
  fin,fout:text;
  st,st1,st2:string;
  i,j,sum,max,min,len:longint;

procedure cut(s1,s2:string);
  var
    o,p,m,len1,len2:longint;
    stt1,stt2:string;
  begin
    len1:=length(s1);
    len2:=length(s2);

          for o:=0 to len1 do
            begin
              stt1:=copy(st1,1,o);

        {      if stt1=copy(st1,len1-o+1,o) then
                begin  }

                  for p:=0 to len2 do
                    begin
                      stt2:=copy(st2,1,p);
                      if (stt1=copy(st1,len1-o+1,o)) and (stt2=copy(st2,len2-p+1,p)) then
                        begin
                          if stt1=stt2 then
                            begin
                              sum:=sum+sqr((len1-length(stt1)))+sqr((len2-length(stt2)));
                              if sum<min
                              then min:=sum;
                                if (stt1<>'') or (stt2<>'')
                                then m:=0
                                else if (stt1<>'') and (stt2<>'')
                                then
                                  begin
                                    cut(stt1,stt2);
                                  end;
                                if sum<min
                                then min:=sum;
                            end
                          else
                            begin
                                if (stt1<>'') or (stt2<>'')
                                then m:=0
                                else if (stt1<>'') and (stt2<>'')
                                then
                                  begin
                                    cut(stt1,stt2);
                                  end;
                              if sum<min
                              then min:=sum;
                            end;
                        end;
                    end;
            end;
  end;

begin
  assign(fin,'savemzx.in');
  assign(fout,'savemzx.out');
  reset(fin);
  rewrite(fout);
  readln(fin,st);
  len:=length(st);
  max:=0;
  for i:=1 to len do
    begin
      st1:=copy(st,1,i);
      for j:=i+1 to len do
        begin
          st2:=copy(st,1,j);
          min:=maxlongint;
          sum:=0;
          cut(st1,st2);



                          if min>max
                          then max:=min;
        end;
    end;
  writeln(fout,max);
  close(fin);
  close(fout);
end.