program flip;
var f,g:text;
        n,m,i,j,k,s,t,smax:longint;
        a:array[1..16,1..16] of longint;
begin
        assign(f,'flip.in');
        reset(f);
        assign(g,'flip.out');
        rewrite(g);
        readln(f,n,m);
        smax:=-maxlongint;
        for i:=1 to n do
                for j:=1 to m do
                        read(f,a[i,j]);
        for i:=0 to (1 shl m)-1 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
                                                        inc(t,-a[k,j]) else
                                                        inc(t,a[k,j]);
                                        if t<-t then inc(s,-t) else
                                        inc(s,t);
                                end;
                        if s>smax then smax:=s;
                end;
        writeln(g,smax);
        close(g);
end.