program info3_overload;
type fliper=1..16;
var n,m:fliper;
    a: array[1..16,1..16] of longint;
    v: array[1..16] of longint;
    i,j,q,w:fliper;
    s,sc,st: longint;
begin
assign(input,'flip.in'); reset(input);
read(n,m);
for i:= 1 to n do for j:= 1 to m do read(a[i,j]);
for i:= 1 to m do
    begin
    s:=0; sc:=0;
    for j:= 1 to n do begin s:=s+a[j,i]; sc:=sc+(a[j,i]*(-1)); end;
    if sc>s then for j:= 1  to n do a[j,i]:=a[j,i]*(-1);
    end;
for i:= 1 to n do
    begin
    s:=0; sc:=0;
    for j:= 1 to m do begin s:=s+a[i,j]; sc:=sc+(a[i,j]*(-1)); end;
    if sc>s then for j:= 1 to m do a[i,j]:=a[i,j]*(-1);
    end;
s:=0;
for i:= 1 to n do for j:= 1 to n do s:=s+a[i,j];
assign(output,'flip.out'); rewrite(output);
write(s);
close(input); close(output);
end.