var f, g:text;
    a:array [1..16, 1..16] of longint;
    n, m, i, j:integer;
    s, s1:longint;
begin assign(f, 'flip.in');
      assign(g, 'flip.out');
      reset(f); rewrite(g);
      readln(f, n, m);
      For i:=1 to n do
         For j:=1 to m do read(f, a[i][j]);
      For i:=1 to n do begin s:=0; s1:=0;
                             For j:=1 to m do begin s:=s+a[i][j];
                                                    s1:=s1-a[i][j];
                                              end;
                             if s1>s then For j:=1 to m do a[i][j]:=0-a[i][j];
                       end;
      For i:=1 to m do begin s:=0; s1:=0;
                             For j:=1 to n do begin s:=s+a[j][i];
                                                    s1:=s1-a[j][i];
                                              end;
                             if s1>s then For j:=1 to n do a[j][i]:=0-a[j][i];
                       end;
      s:=0;
      For i:=1 to n do
         For j:=1 to m do s:=s+a[i][j];
      write(g, s);
      close(f); close(g);
end.