Sequence

Mathematicians often explore numerical sequences like Fibonacci numbers or powers of two, where each term follows a specific rule. But what if the pattern isn't immediately clear?

Your task is to find the N-th term of the sequence: 3, 5, 6, 9, 10, 12, 17, 18, 20, 24, 33 …

Input

A natural number N (N ≤ 2012).

Output

The N-th term of the sequence.

Examples