var f,g:text;
 a:array[1..16,1..16] of longint;
 b,v:array[1..17] of longint;
 n,m,max,nr,j,i:longint;
 begin
 assign(f,'flip.in');reset(f);
 assign(g,'flim.out');rewrite(g);
 read(f,n,m);
 for i:=1 to n do
 begin
 for j:=1 to m do
 begin
 read(f,a[i,j]);
 v[i]:=v[i]+a[i,j];
 end;
 max:=max+v[i];
 end;
 while b[m+1]=0 do begin j:=1;
 while b[j]=1 do begin b[j]:=0;
 for i:=1 to n do v[i]:=v[i]+2*a[i,j];
 j:=j+1;end;b[j]:=1;
 for i:=1 to n do v[i]:=v[i]-2*a[i,j];
 nr:=0;
 for i:=1 to n do
 nr:=nr+abs(v[i]);
 if nr>max then max:=nr;end;
 write(g,max);close(f);close(g);end.