Unsolvable

Consider the following equation:

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 (zi < zi + 1). Your task is: given the number n, find the number zn.

Input

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

Output

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

Examples

Input

1

Output

1

Input

2

Output

3

Input

3

Output

15

inputFormat

Input

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

outputFormat

Output

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

Examples

Input

1

Output

1

Input

2

Output

3

Input

3

Output

15

样例

2

                                                               3

</p>