var a:array[1..16,1..16] of longint;
    v:array[1..16] of 0..1;
    m,n,i,j,s,smax,st:longint;
    f,g:text;
    k:boolean;
begin
assign(f,'flip.in');assign(g,'flip.out');
reset(f);rewrite(g);  
readln(f,m,n);
for i:=1 to m do  
    begin  
    for j:=1 to n do  
        read(f,a[i,j]);  
    readln(f);  
    end;  
smax:=-maxlongint;  
repeat  
      st:=0;  
      for i:=1 to m do  
          begin  
          s:=0;  
          for j:=1 to n do  
              if v[j]=0 then  
                 s:=s+a[i,j]  
              else  
                  s:=s-a[i,j];  
          st:=st+abs(s);  
          end;  
      if st>smax then  
         smax:=st;  
      i:=n;  
      while v[i]=1 do  
            i:=i-1;  
      v[i]:=1;  
      for j:=i+1 to n do  
          v[j]:=0;  
      k:=true;  
      for i:=1 to n do  
          if v[i]=0 then  
             begin  
             k:=false;  
             break;  
             end;  
until k=true;  
write(g,smax);  
close(f);close(g);  
end.