const
 inp='';

var
 f:text;
 a:array[1..9,1..99]of 0..1;
 b:array[1..9]of integer;
 c:array[1..99]of integer;
 n,m,l:shortint;

procedure print;
 var
  e,max:shortint;
 begin
  for l:=1 to m do
   begin
    max:=0;
    for e:=1 to n do if a[l,e]=1 then max:=max+1;
    writeln(max);
    for e:=1 to n do if a[l,e]=1 then write(c[e],' ');
    writeln;
   end;
  halt;
 end;

procedure found(i:shortint);
 var
  j:shortint;
 begin
  for j:=1 to m do
   if b[j]-c[i]>=0 then
    begin
     a[j,i]:=1;b[j]:=b[j]-c[i];
     if i<>1 then found(i-1) else print;
     a[j,i]:=0;b[j]:=b[j]+c[i];
    end;
 end;

begin
 fillchar(a,sizeof(a),0);
 assign(f,inp);reset(f);
 readln(f,n,m);
 for l:=1 to n do readln(f,c[l]);
 for l:=1 to m do readln(f,b[l]);
 close(f);
 found(n);
end.