program p1;
var n,m:byte;
    f,g:text;
    i,nr,nr1,j,k,s,u1,u,i1,i2,k1,max:longint;
    a,b:array[0..20,0..20] of longint;
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]);   end;
                  readln(F);
                  end;
 for i:=1 to (1 shl m) do begin
        s:=0;
        for j:=1 to n do
                 begin
                 k:=0;
                 for i1:=1 to m do begin
                        if i and (1 shl (i1-1))<>0 then k:=k-a[j,i1]
                                 else k:=k+a[j,i1];
                        if k<-k then s:=s-k
                                else s:=s+k;
                        {writeln(g,s); }

                        if s>max then
                                begin
                                max:=s;
                                end;  end;
                 end;
        end;
writeln(g,max);
close(F);
close(G);
end.