The Magic Spiral Thrill

In this problem, you are given an integer d representing the day number of the event "The Magic Spiral". The thrill level on day d is calculated as follows:

For d = 1, the thrill level is 1. For any d > 1, the thrill level is computed using the formula:

$$T(d)=\left(\sum_{i=1}^{d-1} T(i)\right)+1$$

This recurrence relation quickly reveals that T(d) = 2^{d-1}. Your task is to compute the thrill level on the given day d.

Input/Output Note: Your program should read input from stdin and write the output to stdout.

inputFormat

The input consists of a single integer d (1-indexed) provided on a single line, which represents the day number.

outputFormat

Output a single line containing the thrill level on the d-th day, which is computed as 2^(d-1).

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