Problems > Perrin Numbers Modulo

Perrin Numbers Modulo

Difficulty: 1750 4000 ms 128 MB

math matrix-exponentiation

The sequence obeys Q(0)=3, Q(1)=0, Q(2)=2 and Q(n)=Q(n−2)+Q(n−3). Print term N modulo 109+7.

Input: one integer N.

Output: term N mod 109+7.

Constraints:

  • 0 ≤ N ≤ 1018

Sample Tests

Input 1
5
Output 1
5
Input 2
0
Output 2
3

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