Tribonacci numbers
Description
Tribonacci numbers are a sequence of numbers, defined as follows:
- t0 = t1 = 0,
- t2 = 1,
- ti = ti - 1 + ti - 2 + ti - 3.
You are given n; calculate n-th tribonacci number modulo 26.
The only line of input contains an integer n (1 ≤ n ≤ 1000).
Output n-th tribonacci number modulo 26.
Input
The only line of input contains an integer n (1 ≤ n ≤ 1000).
Output
Output n-th tribonacci number modulo 26.
Samples
4
2
9
18