Holey Square Tiling

Time Limit: 10000ms
Memory Limit: 131072KB
This problem will be judged on PKU. Original ID: 3472
64-bit integer IO format: %lld      Java class name: Main

Description

Given a square of size n + 2 with a square hole of size n − 2 in the middle (see the figure below), calculate the number of different ways to tile it with dominoes of size 1 × 2.

Input

The input consists of multiple test cases. Each test case contains only one integer n (3 ≤ n ≤ 104). Process util EOF is met.

Output

For each test case, output the desired number in decimal using the comma as the thousand separator.

Sample Input

3
50

Sample Output

196
401,520,777,816,387,690,468,975,409,805,843,797,460,004

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