var a:array[1..16,1..16]of longint;
    b,l:array[1..17]of longint;
    n,m,max,s,i,j:longint;
    f,g:text;

begin
assign(f,'flip.in');
reset(f);
assign(g,'flip.out');
rewrite(g);
readln(f,n,m);
for i:=1 to n do begin
   for j:=1 to m do begin
      read(f,a[i,j]);
      l[i]:=l[i]+a[i,j];
   end;
   readln(f);
   max:=max+l[i];
end;
while b[m+1]=0 do begin
   j:=1;
   while b[j]=1 do begin
      b[j]:=0;
      for i:=1 to n do l[i]:=l[i]+2*a[i,j];
      j:=j+1;
   end;
   b[j]:=1;
   for i:=1 to n do begin
      l[i]:=l[i]-2*a[i,j];
   end;
   s:=0;
   for i:=1 to n do s:=s+abs(l[i]);
   if s>max then max:=s;
end;
write(g,max);
close(g);
end.