#abc171f. [abc171_f]Strivore

[abc171_f]Strivore

Problem Statement

How many strings can be obtained by applying the following operation on a string SS exactly KK times: "choose one lowercase English letter and insert it somewhere"?

The answer can be enormous, so print it modulo (109+7)(10^9+7).

Constraints

  • KK is an integer between 11 and 10610^6 (inclusive).
  • SS is a string of length between 11 and 10610^6 (inclusive) consisting of lowercase English letters.

Input

Input is given from Standard Input in the following format:

KK SS

Output

Print the number of strings satisfying the condition, modulo (109+7)(10^9+7).


Sample Input 1

5
oof

Sample Output 1

575111451

For example, we can obtain proofend, moonwolf, and onionpuf, while we cannot obtain oofsix, oofelevennn, voxafolt, or fooooooo.


Sample Input 2

37564
whydidyoudesertme

Sample Output 2

318008117