var n,m,i,j,lim,q,sum,max,s,x:longint;
v,v1:array[1..16,1..16] of longint;
f,g:text;
begin
assign(f,'flip.in');reset(f);
assign(g,'flip.out');rewrite(g);
read(f,n,m);
for i:=1 to n do
 for j:=1 to m do
  read(f,v[i,j]);
lim:=(1 shl n)-1;
for i:=0 to lim do begin
 for j:=1 to n do begin
  if i and (1 shl (j-1))>0 then x:=-1
  else x:=1;
  for q:=1 to m do v1[j,q]:=x*v[j,q];
                  end;
 sum:=0;
 for j:=1 to m do begin
  s:=0;
  for q:=1 to n do
   s:=s+v1[q,j];
  if s<0 then s:=-s;
  sum:=sum+s;
                  end;
 if sum>max then max:=sum;
                    end;
write(g,max);
close(f);
close(g);
end.