var a,b,c:array[1..16,1..16] of longint;
    smax:longint;
    st:array[1..16] of byte;
    n,m,i,j:integer;
    f,g:text;
procedure verificare(k:integer);
var i,j:integer;
    s1,s2:longint;
begin
for i:=1 to k do
        if st[i]=1 then
                c[i]:=a[i]
        else
                c[i]:=b[i];
s2:=0;
for i:=1 to n do
        begin
        s1:=0;
        for j:=1 to m do
                s1:=s1+c[i,j];
        if s1<0 then
                s2:=s2-s1
        else
                s2:=s2+s1;
        end;
if smax<s2 then
        smax:=s2;
end;
procedure generare(k:integer);
begin
if k=n+1 then
        verificare(k-1)
else
        begin
        st[k]:=1;
        generare(k+1);
        st[k]:=-1;
        generare(k+1);
        end;
end;




begin
assign(f,'flip.in');
assign(g,'flip.out');
reset(f);
rewrite(g);
readln(f,n,m);
for i:=1 to n do
        begin
        for j:=1 to m do
                begin
                readln(f,a[i,j]);
                b[i,j]:=-a[i,j];
            end;
        readln(f);
        end;
smax:=-maxlongint;
generare(1);
writeln(g,smax);
close(f);
close(g);
end.