program flip1;
 type mat= array[1..25,1..25]of integer;
 var m,n:byte;
     a:mat;
 procedure citire;
 var f:text;
     i,j:byte;
 begin
 assign(f,'flip.in');
 reset(f);
 read(f,n);
 readln(f,m);
 for i:=1 to n do
 begin
 for j:=1 to m do
 read(f,a[i,j]);
 readln(f);
 end;
 close(f);
 end;
 function flip(a:mat):word;
 var i,j:byte;
     s,s1:longint;
 begin
 for i:=1 to n do
 begin
 s:=0;
 s1:=0;
 for j:=1 to m do
 begin
 s:=s+a[i,j];
 s1:=s1-a[i,j];
 end;
 if s1>s then
 for j:=1 to m do
 a[i,j]:=0-a[i,j];
 end;
 for j:=1 to m do
 begin
 s:=0;
 s1:=0;
 for i:=1 to n do
 begin
 s:=s+a[i,j];
 s1:=s1-a[i,j];
 end;
 if s1>s then
 for i:=1 to n do
 a[i,j]:=0-a[i,j];
 end;
 s:=0;
 for i:= 1 to n do
 for j:= 1 to m do
 s:=s+a[i,j];
 flip:=s;
 end;
 procedure afisare;
 var f:text;
 begin
 assign(f,'flip.out');
 rewrite(f);
 write(f,flip(a));
 close(f);
 end;
 begin
 citire;
 afisare;
 end.