program flip;
type vec=array[1..16] of longint;
var pi,pj,mi,mj: vec;
    m,n,i,j,x,suma,aux: integer;
    t: text;
begin
   assign(t,'flip.in'); reset(t);
   read(t,m,n);
   suma:=0;
   for i:=1 to m do
     begin
        pi[i]:=0;
        mi[i]:=0;
     end;
   for j:=1 to n do
     begin
        pj[j]:=0;
        mj[j]:=0;
     end;
   readln(t);
   for i:=1 to m do
    begin
      for j:=1 to n do
       begin
         read(t,x);
         if x>=0 then begin
                       pi[i]:=pi[i]+x;
                       pj[j]:=pj[j]+x;
                       suma:=suma+x;
                      end;
         if x<0 then begin
                       suma:=suma+x;
                       mi[i]:=mi[i]+abs(x);
                       mj[j]:=mj[j]+abs(x);
                      end;
       end;
       readln(t);
    end;
     close(t);
    {comuta linii}
    for i:=1 to m do
      if pi[i]<mi[i] then begin
                            aux:=pi[i];
                             pi[i]:=mi[i];
                             mi[i]:=aux;
                          end;
    {comuta coloane}
     for i:=1 to n do
      if pj[i]<mj[i] then begin
                              aux:=pj[i];
                             pj[i]:=mj[i];
                             mj[i]:=aux;
                          end;
    assign(t,'flip.out'); rewrite(t);
   for i:=1 to n do
    begin
      suma:=suma+pi[i]-mi[i];
    end;
     write(t,suma);
    close(t);
end.