一脸懵逼！二脸懵逼！三脸懵逼！怎么只有50分！

var
  n,i,j,s,len:longint;
  m:string;
  a,b:array[1..1000] of longint;
function fun:boolean;
  var i,j:longint;
begin
  i:=1;j:=len;
  while (a[i]=a[j])and(i<j) do begin
    inc(i);dec(j);
  end;
  if i>j then exit(true)
  else exit(false);
end;
procedure jia;
var
  i:longint;
begin
  for i:=1 to len do b[len-i+1]:=a[i];
  for i:=1 to len do a[i]:=a[i]+b[i];
  for i:=1 to len do begin
    a[i+1]:=a[i+1]+a[i] div n;
    a[i]:=a[i] mod n;
  end;
  if a[len+1]>0 then inc(len);
end;
begin
  readln(n);
  readln(m);
  len:=length(m);
  for i:=1 to len do
    if (m[i]>='0') and (m[i]<='9') then a[len-i+1]:=ord(m[i])-ord('0')
      else a[len-i+1]:=ord(m[i])-ord('A')+10;
  s:=0;
  while not(fun)and(s<30) do begin
    jia;
    inc(s);
  end;
  if s>30 then write('Impossible!')
    else write('STEP=',s);
end.
这不可能！一脸懵逼！二脸懵逼！三脸懵逼！四脸懵逼！五脸懵逼！无限懵逼！！怎么只有50分！