var f,g:text;
    N,M,i,j,Icom,Jcom:integer;
    A:array[1..16,1..16] of longint;
    S1,S2:array[1..16] of longint;
    m1,m2,S:longint;
  begin
  assign(f,'flip.in');
  assign(g,'flip.out');
   reset(f);
   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;
   for i:=1 to N do 
     begin
     S1[i]:=0;
      for j:=1 to M d
       S1[i]:=S1[i]+A[i,j];
     end; 
        for j:=1 to M do 
     begin
     S2[j]:=0;
      for i:=1 to N do
       S2[j]:=S2[j]+A[i,j];
      end; 
       m1:=S1[1]; Icom:=1;
        for i:=1 to N do
       if S1[i]<m1 then begin m1:=S1[i]; Icom:=i; end;
       m2:=S2[1]; Jcom:=1;
        for j:=1 to M do
         if S2[j]<m2 then begin m2:=S2[j]; Jcom:=j end;
      for i:=1 to N do A[i,Jcom]:=-A[i,Jcom];
      for j:=1 to M do A[Icom,j]:=-A[Icom,j];
       A[Icom,Jcom]:=-A[Icom,Jcom];
        S:=0;
         for i:=1 to N do
          for j:=1 to M do
           S:= S+A[i,j];
       write (g,S);
        close(f);
        close(g);
         end.