type mat=array [1..17,1..17] of longint;
var f:text;
    a:mat;
    i,j,m,n:integer;

begin
assign(f, 'flip.in');
reset(f);
read(f,n,m);
for i:=1 to n do
 for j:=1 to m do
  begin
  read(f,a[i,j]);
  inc(a[i,m+1],a[i,j]);
  inc(a[n+1,j],a[i,j]);
  end;
close(f);
for i:=1 to n do
  if a[i,m+1]<0 then
   begin
    a[i,m+1]:=abs(a[i,m+1]);
    for j:=1 to m do
     a[n+1,j]:=a[n+1,j]-2*a[i,j];
   end;

for j:=1 to m do
 if a[n+1,j]<0 then
  begin
   a[n+1,j]:=abs(a[n+1,j]);
    for i:=1 to n do
     a[i,m+1]:=a[i,m+1]-2*a[i,j];
  end;
for i:=1 to n do
 a[n+1,m+1]:=a[n+1,m+1]+a[i,m+1];
assign(f, 'flip.out');
 rewrite(f);
write(f,a[n+1,m+1]);
close(f);
end.