Consider the following equation:

$\text{[math]}$ where sign [a] represents the integer part of number a.

Let's find all integer z (z > 0), for which this equation is unsolvable in positive integers. The phrase "unsolvable in positive integers" means that there are no such positive integers x and y (x, y > 0), for which the given above equation holds.

Let's write out all such z in the increasing order: z₁, z₂, z₃, and so on (z_i < z_i + 1). Your task is: given the number n, find the number z_n.

Input

The first line contains a single integer n (1 ≤ n ≤ 40).

Output

Print a single integer — the number z_n modulo 1000000007 (10⁹ + 7). It is guaranteed that the answer exists.

Unsolvable

Examples