var m,n:byte;
i,j,max,e,ee,k:longint;
x:array[1..16] of integer;
f:text;
a:array[1..16,1..16] of longint;
procedure inapoi(p:longint);
begin
x[p]:=1;
if p=n then
begin
e:=0;
for j:=1 to m do
begin
ee:=a[1,j];
for k:=2 to n do
ee:=ee+x[k]*a[k,j];
e:=e+abs(ee);
end;
if max<e then max:=e;
end
else inapoi(p+1);
x[i]:=-1;
if p=n then
begin
e:=0;
for j:=1 to m do
begin
ee:=a[1,j];
for k:=2 to n do
ee:=ee+x[k]+a[k,j];
e:=e+abs(ee);
end;
if max<e then max:=e;
end
else inapoi(p+1);
end;
begin
assign(f,'flip.in');reset(f);
read(f,n);
readln(f,m);
for i:=1 to n do
begin
for j:=1 to m do
read(f,a[i,j]);
readln(f);
end;
close(f);
max:=0;
inapoi(1);
assign(f,'flip.out');rewrite(f);
write(f,max);
close(f);
end.