var  a:array[1..16,1..16] of longint;
     n,m:byte;
     smax:longint;
     f:text;

procedure citire;
var i,j:byte;
begin
assign(f,'flip.in'); reset(f);
readln(f,n,m);
for i:=1 to n do
    for j:=1 to m do read(f,a[i,j]);
close(f);
end;

procedure rezolvare;
var i,s,t:longint;
    k,j:byte;
begin
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 smax<s then smax:=s;
    end;
end;

procedure afisare;
var g:text;
begin
assign(g,'flip.out'); rewrite(g);
writeln(g,smax);
close(g);
end;

begin
citire;
rezolvare;
afisare;
end.