## Problem B: Three powers

Consider the set of all non-negative integer powers of 3.

*S* = { 1, 3, 9, 27, 81, ... }
Consider the sequence of all subsets of *S* ordered by the
value of the sum of their elements. The question is simple: find the set
at the *n*-th position in the sequence and print it in increasing
order of its elements.

Each line of input contains a number *n*, which is a positive
integer with no more than 19 digits. The last line of input contains
0 and it should not be processed.

For each line of input, output a single line displaying the
*n*-th set as described above, in the format used in the sample
output.

### Sample input

1
7
14
783
1125900981634049
0

### Output for sample input

{ }
{ 3, 9 }
{ 1, 9, 27 }
{ 3, 9, 27, 6561, 19683 }
{ 59049, 3486784401, 205891132094649, 717897987691852588770249 }

*P. Rudnicki*