program flip;
var a:array[1..16,1..16] of longint;
    f : text;
    n,m,i,j,x,y : byte;
    s,max : longint;
procedure suma;
begin
    s := 0;
    for i := 1 to n do
        for j := 1 to m do
            if (x=i) or (y=j) then
                s := s + a[i,j]*(-1)
            else s := s + a[i,j];
end;

begin
    assign(f,'flip.in'); reset(f);
    readln(f,n,m);
    for i := 1 to n do begin
        for j := 1 to m do
            read(f,a[i,j]);
        readln(f);
        end;
    close(f);
    x := 1; y := 1; suma; max := s;
    for x := 1 to n do
        for y := 1 to m do begin
            suma;
            if s > max then max := s;
            end;
    assign(f,'flip.out'); rewrite(f);
    write(f,max); close(f);
end.