program ex(f1,f2);
 type
  zn=array [1..30000] of integer;
 var
  a:zn; i,j,k,m,n,now,p,ans:longint; max:longint;
  f1,f2:text; l,r:longint;
 procedure qsort(left,right:longint);
  var l,r,x,y:integer;
  begin
   l:=left; r:=right;
   x:=a[(l+r) div 2];
   repeat
    while a[l]<x do inc(l);
    while a[r]>x do dec(r);
     if l<=r then
      begin
       y:=a[l];
       a[l]:=a[r];
       a[r]:=y;
       inc(l);
       dec(r);
      end;

   until l>r;
   if l<right then qsort(l,right);
   if r>left then qsort(left,r);
  end;



 begin
  assign(f1,'group.in'); assign(f2,'group.out');reset(f1); rewrite(f2);
  readln(f1,max);
  readln(f1,n);
  for i:=1 to n do readln(f1,a[i]);
  qsort(1,n);
  p:=0; now:=0; ans:=0; ans:=n;
  l:=1; r:=n;
  while r>=l do
   begin
    if (a[l]+a[r]<=max)and(l<>r)
     then begin
          dec(ans);
          dec(r);
          inc(l);
          end
     else r:=r-1;
   end;
  writeln(f2,ans);
  close(f1);
  close(f2);
 end.