var  m:array[1..20,1..20] of longint;
   k,l:                      longint;
   i,j:                      longint;
x,y,x1:                      longint;
  s,s1:array[1..20]       of longint;
 a,aux:                      longint;
   sum:                      longint;
     t:                         text;
       begin
        assign(t,'flip.in');
        reset(t);
        readln(t,k,l);
        a:=-1;
        for i:=1 to k do
        for j:=1 to l do
                         read(t,m[i,j]);
        close(t);
        for x:=0 to ((1 shl k)-1) do begin
          y:=0;x1:=x;
          while (x1<>0) do begin
            inc(y);
            s[y]:=x1 mod 2;
            x1:=x1 div 2;
          end;
          sum:=0;
          for i:=1 to k do
          begin
            aux:=0;
            for j:=1 to l do
             begin
               if s[j]=1 then aux:=aux-m[i,j] else aux:=aux+m[i,j];
               aux:=abs(aux);
             end;
            sum:=sum+aux;
          end;
          if sum>a then a:=sum;
          for i:=1 to y do s[i]:=0;
         end;
         assign(t,'flip.out');
         rewrite(t);
         writeln(t,a);
         close(t);
        end.