Tri Tiling

Time Limit: 1000 ms Memory Limit: 65536 KiB

Problem Description

Problem Description

In how many ways can you tile a 3xn rectangle with 2x1 dominoes? Here is a sample tiling of a 3x12 rectangle.


Input consists of several test cases followed by a line containing -1. Each test case is a line containing an integer 0 ≤ n ≤ 30.


For each test case, output one integer number giving the number of possible tilings.

Sample Input

2 8 12 -1

Sample Output

3 153 2131