Program flip_arena;
var fl : array[0..100,0..100] of longint;
    maxim,n,m:longint;
procedure citire;
var fi : text;
    i,j:integer;
begin
     assign(fi,'flip.in'); reset(fi); readln(fi,n,m);
     for i:=1 to n do for j:=1 to m do read(fi,fl[i,j]);
     close(fi);
end;

procedure max;
var fo : text;
    i,j,t,k,sum:longint;
begin
     for i:=1 to (1 shl m)do begin sum:=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-fl[k,j]
                                                                                                   else t:=t+fl[k,j];
                                                          if t<-t then sum:=sum-t else sum:=sum+t;
                                                          end;
                                                 if sum>maxim then maxim:=sum;
                                                  end;
     assign(fo,'flip.out'); rewrite(fo); writeln(fo,maxim); close(fo);
end;

begin
      citire;
      max;
end.