var a: array[0..100,0..100] of longint;
    maxim, n, m, t, sum, k:longint;
    fi, fo : 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,a[i,j]);
     close(fi);
   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-a[k,j]
                                                                                    else t:=t+a[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.