You are given two integers $N$ and $K.$ You have to find the total number of strings of length $N,$ which satisfy the following conditions:

String only contains lowercase english characters.

No K consecutive characters of the string are same.

Return the answer by taking modulo with $1e9+7.$

Example $1$:

input:

$N=2.K=2$

Output:

$650$

Explanation:

Total number of possible strings with $2$ characters is ${26}^{**}26$ in which $26$ strings have $2$ consecutive characters like $\{$aa$,$bb$,.$ Therefore the answer is ${26}^{**}26-26=650.$

Example $2$: