program ceva;
type
tabel=array [0..17,0..17] of longint;
tab=array [0..101] of longint;
var
v:tab;
t:tabel;
n,m,i,j,k,s,ss,max:longint;
f1,f2:text;
begin
assign (f1,'flip.in');
assign (f2,'flip.out');
reset (f1);
rewrite (f2);
readln (f1,n,m);
for i:=1 to n do
for j:=1 to m do
read (f1,t[i,j]);
while (v[m]=0) do
begin
for i:=1 to m do
begin
if v[i]=1 then v[i]:=0 else
begin
v[i]:=1;
break;
end;
end;
ss:=0;
for j:=1 to n do
begin
s:=0;
for k:=1 to m do
if v[k]=1 then s:=s-t[j,k] else
s:=s+t[j,k];
if s<0 then s:=s*(-1);
ss:=ss+s;
end;
if ss>max then max:=ss;
end;
writeln (f2,max);
close (f1);
close (f2);
end.