program razy;
var a:array[1..100,1..100] of integer;
    c:array[1..100] of integer;
    f,g:text;
    max,i,j,n,m,sum,q,d,s,imax,jmax:integer;
begin
assign(f,'flip.in');reset(f);
assign(g,'flip.out');rewrite(g);
readln(f,n,m);
for i:=1 to n do
  for j:=1 to m do
    read(f,a[i,j]);
max:=-maxint;
for i:=1 to n do
  begin
  s:=0;d:=0;
  for j:=1 to m do
    begin
    s:=s+a[i,j];
    c[j]:=a[i,j]*(-1);
    d:=d+c[j];
    end;
  q:=d-s;
  if q>max then begin imax:=i;
                      max:=q;
                      end;
  end;
max:=-maxint;
for j:=1 to m do
  begin
  s:=0;d:=0;
  for i:=1 to n do
    begin
    s:=s+a[i,j];
    c[j]:=a[i,j]*(-1);
    d:=d+c[j];
    end;
  q:=d-s;
  if q>max then begin jmax:=j;
                      max:=q;
                      end;
  end;
for j:=1 to m do
  a[imax,j]:=a[imax,j]*(-1);
for i:=1 to n do
  a[i,jmax]:=a[i,jmax]*(-1);
sum:=0;
for i:=1 to n do
  for j:=1 to m do
    sum:=sum+a[i,j];
writeln(g,sum);
close(f);close(g);
end.