Program p1;
var  a : array[1..100,1..100] of longint;
n,m,max : longint;

 
 
Procedure ReadData;
var fin : text;
i,j : integer;
begin
assign(fin,'flip.in');
reset(fin);
readln(fin,n,m);
for i:=1 to n do
for j:=1 to m do
read(fin,a[i,j]);
close(fin);
end;
 
 
Procedure CheckMax;
var s,i,j,t,k : longint;
fout : text;
 begin
    for i:=1 to (1 shl m) do
        begin
           s:=0;
           for k:=1 to n do
              begin
                 t:=0;
                 for j:=1 to m do
                 if i and (1 shl (j-1))>0 then t:=t-a[k,j] else
                 t:=t+a[k,j];
                 if t<-t then s:=s-t else s:=s+t;
              end;
          if s>max then max:=s;
        end;
assign(fout,'flip.out');
rewrite(fout);
writeln(fout,max);
close(fout);
end;
 
begin
ReadData;
CheckMax;
end.