var f:text;
    i,j,a,b,n,m,x,y,o,p:longint;
    v:array[1..16,1..16] of longint;
    gasit:boolean;

function sl(x,a:integer):longint;
var i:integer;
    k:longint;
begin
k:=0;
 for i:=1 to m do
  inc(k,v[x,i]*a);
sl:=k;
end;

function sc(x,a:integer):longint;
var i:integer;
    k:longint;
begin
k:=0;
 for i:=1 to n do
  inc(k,v[i,x]*a);
sc:=k;
end;


begin
assign(f,'flip.in');reset(f);
readln(f,n,m);

for i:=1 to n do for j:=1 to m do  read(f,v[i,j]);close(f);

gasit:=true;
while gasit do
 begin
  gasit:=false;
   a:=0;b:=0;

   for i:=1 to m do
       begin
        x:=sc(i,1);y:=sc(i,-1);
        x:=y-x;
         if x>a then begin a:=x;p:=i;end;
       end;
   for i:=1 to n do
      if (sl(i,1)<sl(i,-1))and(sl(i,-1)>b) then b:=sl(i,-1);
   if (a>0)or(b>0) then
   begin
    if a>b then
           begin for i:=1 to m do v[i,a]:=v[i,a]*-1;end
       else begin for i:=1 to n do v[b,i]:=v[b,i]*-1;end;
   gasit:=true;end;
 end;

a:=0;
for i:=1 to n do
 for j:=1 to m do inc(a,v[i,j]);
writeln(a);
end.