===== Prelude to Self-describing Sequence ======

First, start by reading the problem statement for [[http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=33&page=show_problem&problem=990|Self-describing Sequence]].

For this prelude, create an array, ''fr'', that contains the index of each place in ''f(n)'' where ''f(n)'' changes values (that is, where the next run of identical values appears).

  n     1   2   3   4   5   6   7   8   9  10  11  12 13 14 15 16
  f(n)  1   2   2   3   3   4   4   4   5   5   5   6  6  6  6  7
  fr[n] 1   2   4   6   9  12  16   ...

This array is a kind of run-length encoding of function ''f(n)''.

===== Input =====

Input consists of a sequence of integers, one per line.  The last entry is a 0, which should not be processed.

===== Output =====

For each non-zero input value, ''k'', print the value of ''n'' where ''f(n)'' changes to ''k''.

===== Sample Input =====

<code>
7
0
</code>

===== Sample Output =====

<code>
16
</code>