var f,g:text;   
    a:array[1..16,1..16] of longint;      
    s,ss,smax,hhh:longint;      
    k,i,j,n,m:byte;      
    x:array[0..16] of byte;      
begin     
assign(f,'flip.in');reset(f);
assign(g,'flip.out');rewrite(g);
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;
    k:=1;
while k>0 do
    begin
    if x[k]<2 then x[k]:=x[k]+1;
    if k=n then begin
                ss:=0;
    for j:=1 to m do begin
                     s:=0;
                     for i:=1 to n do
                         begin
                         if x[i]=2 then s:=s-a[i,j]
                         else s:=s+a[i,j];
                         end;
                     if s<0 then ss:=ss-s
                        else ss:=ss+s;
                        end;
                     if ss>smax then smax:=ss;
                     while x[k]=2 do
                           begin
                           k:=k-1;
                           end;
                end
                else begin
                     k:=k+1;
                     x[k]:=0;
                     end
    end;
write(g,smax);
close(f);
close(g);
end.