var n,m,i,j,k,s,t,smax:longint;
    f,g:text;
    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:=0;
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 smax<s then smax:=s;
end;
writeln(g,smax);
close(g);
end.