program flip;
var smax,s,ss,sm:longint;
    m,n,i,j,k:byte;
    a:array[1..16,1..16] of longint;
    f,h:text;
function s1(i:byte):longint;
var j:byte;
    s:longint;
begin
s:=0;
for j:=1 to m do
 s:=s+a[i,j];
s1:=s;
end;
function s2(i:byte):longint;
var j:byte;
    s:longint;
begin
s:=0;
for j:=1 to n do s:=s+a[j,i];
s2:=s;
end;
function s3:longint;
var j,i:byte;
    s:longint;
begin
s:=0;
for i:=1 to n do
 for j:=1 to m do s:=s+a[i,j];
s3:=s;
end;
begin
assign(f,'flip.in');
assign(h,'flip.out');
reset(f);rewrite(h);
readln(f,n,m);
smax:=0;
for i:=1 to n do
 for j:=1 to m do
  begin
   read(f,a[i,j]);
   smax:=smax+a[i,j];
  end;
for i:=1 to n do
 begin
 s:=-s1(i);
 ss:=s3;
 if s>0 then begin
               if ss+2*s>smax then
                begin
                 smax:=2*s+ss;
                 for j:=1 to m do a[i,j]:=a[i,j]*(-1);
                end;
              end;
 end;
for i:=1 to m do
 begin
 s:=-s2(i);
 ss:=s3;
 if s>0 then begin
               if ss+2*s>smax then
                begin
                 smax:=2*s+ss;
                 for j:=1 to n do a[i,j]:=a[i,j]*(-1);
                end;
              end;
 end;
writeln(h,smax);
close(f);close(h);
end.