program flip;
var f,g:text;
a:array [1..16,1..16] of longint;
s,ss,smax:longint;
k,i,j,n,m:byte;
x:array [0..16] of byte;
begin
assign (f,'flip.in');
assign (g,'flip.out');
reset (f);
rewrite (g);
read (f,m,n);
for i:=1 to n do
    begin
    for j:=1 to m do read (f,a[i,j]);
    readln(f);
    end;
k:=1;
for i:=1 to n do x[i]:=0;
while k>0 do begin
if x[k]<2 then x[k]:=x[k]+1;
if k=n then begin
   ss:=0;
   for j:=1 to m do begin
       s:=0;
       for i:=1 to n do
        begin
         if x[i]=2 then s:=s-a[i,j]
                   else s:=s+a[i,j];
                   end;
         if s<0 then ss:=ss-s
                else ss:=ss+s;
                end;
                if ss>smax then smax:=ss;
         while x[k]=2 do
                      begin
                      k:=k-1
                      end;
                      end
                      else
                      begin
                      k:=k+1;
                      x[k]:=0;
                      end
                      end;
write (g,smax);
close (f);
close(g)
end.