Tribonacci

题目描述

[problemUrl]: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=279&page=show_problem&problem=3914 [PDF](https://uva.onlinejudge.org/external/124/p12470.pdf) ![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12470/4f23161835010a90f944a0b1ae366897f8921d42.png)

输入输出格式

输入格式


![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12470/5b9c69344ba0dd229a994c2cc479efe71e3f6df3.png)

输出格式


![](https://cdn.luogu.com.cn/upload/vjudge_pic/UVA12470/95224bb7939fd2ab5e58eb6e7ac88616b56354b3.png)

输入输出样例

输入样例 #1

1
2
3
4
5
6
7
8
9
10
100
10000
10000000
100000000000
10000000000000000
0

输出样例 #1

0
1
2
3
6
11
20
37
68
125
616688122
335363379
272924536
48407255
163452242