Program joc_flip;
 var i,j,n,m,s,poz,neg,k:longint;
  f,g:text;
   a:array[1..20,1..20] of longint;
  begin
   assign(f,'flip.in'); reset(f);
   assign(g,'flip.out'); rewrite(g);
   read(f,n,m);
    for i:=1 to n do
     for j:=1 to m do
      read(f,a[i,j]);

   for i:=1 to n do
    begin poz:=0; neg:=0;

    for j:=1 to m do
     if a[i,j]>0 then poz:=poz+a[i,j] else neg:=neg+a[i,j];

      if (abs(neg)>poz) then begin for k:=1 to m do a[i,k]:=a[i,k]*(-1);   end;

     end;

   for i:=1 to m do
    begin poz:=0; neg:=0;

    for j:=1 to n do
     if a[j,i]>0 then poz:=poz+a[j,i] else neg:=neg+a[j,i];

      if (abs(neg)>poz) then begin for k:=1 to n do a[k,i]:=a[k,i]*(-1); end;

      end;

      s:=0;
     for i:=1 to n do
      for j:=1 to m do
          s:=s+a[i,j];

          writeln(g,s);
          close(f);
          close(G);
      end.