var     f,g:text;
        v:array[1..16,1..16] of longint;
        sum:array[1..16] of longint;
        ok:array[1..16] of boolean;
        i,j,n,m,s,k,max:longint;
        ll:boolean;

procedure   back(poz:integer);
begin
if poz<=k then begin
 ok[poz]:=true;
 back(poz+1);
 ok[poz]:=false;
 back(poz+1);
end
else begin
 {if ll then begin}
  fillchar(sum,sizeof(sum),0);
  for i:=1 to n do
   for j:=1 to m do
    if ok[i] then sum[j]:=sum[j]-v[i,j]
             else sum[j]:=sum[j]+v[i,j];
  s:=0;
  for i:=1 to m do
   s:=s+abs(sum[i]);
  if max<s then max:=s;
 {end
 else begin
  fillchar(sum,sizeof(sum),0);
  for i:=1 to m do
   for j:=1 to n do
    if ok[i] then sum[j]:=sum[j]-v[j,i]
             else sum[j]:=sum[j]+v[j,i];
  s:=0;
  for i:=1 to n do
   s:=s+abs(sum[i]);
  if max<s then max:=s;
 end;}
end;
end;


begin
assign (f,'flip.in');reset(f);
assign (g,'flip.out');rewrite (g);
readln (f,n,m);
if n<m then begin
 k:=n;
 ll:=true;
end
else begin
 k:=m;
 ll:=false;
end;
for i:=1 to n do
 for j:=1 to m do
  read(f,v[i,j]);
max:=0;
back(1);
writeln (g,max);
close(f);close(g);
end.