program flipo;
type matt = array [1..17,1..17] of longint;
var A : matt;
    m,n,i,j,k : integer;
    S,Sp,r,t : longint;
    f : text;
begin
assign(f,'flip.in');
reset(f);
readln(f,m,n);

for i := 1 to n do begin
for j := 1 to n do
read(f,A[i,j]);
readln(f);
end;
close(f);

k := 0;
repeat
k := k+1;

i := 0;
repeat
i := i+1;
r := 0;
t := 0;
for j := 1 to m do begin
r := r+A[i,j];
t := t-A[i,j];
end;
if t > r then
        for j := 1 to m do
        A[i,j] := A[i,j]*(-1);
until i=n;


i := 0;
repeat
i := i+1;
r := 0;
t := 0;
for j := 1 to n do begin
r := r+A[j,i];
t := t-A[j,i];
end;
if t > r then
        for j := 1 to n do
        A[j,i] := A[j,i]*(-1);
until i=m;

until k=5;



S := 0;
for i := 1 to n do
for j := 1 to n do
S := S+A[i,j];

write('S=',S);
readln;


end.