Program flip;
var f: array[0..100,0..100] of longint;
    max,n,m,i,j,t,k,sum:longint;
    fi,fo:text;
begin
assign(fi,'flip.in');
 assign(fo,'flip.out');
reset(fi);
 rewrite(fo);
readln(fi,n,m);
 for i:=1 to n do
         for j:=1 to m do
                  read(fi,f[i,j]);
 for i:=1 to (1 shl m)do begin
                          sum:=0;
                           for k:=1 to n do begin
                                             t:=0;
                                for j:=1 to m do if i and (1 shl(j-1))>0 then t:=t-f[k,j]
                                                                          else t:=t+f[k,j];
                                     if t<-t then sum:=sum-t else sum:=sum+t;
                                                          end;
                           if sum>max then max:=sum;
                            end;
  writeln(fo,max);
 close(fo);
end.