Given two words A and B, and a dictionary, C, find the length of shortest transformation sequence from A to B, such that:

You must change exactly one character in every transformation.
Each intermediate word must exist in the dictionary.

Note:

Return 0 if there is no such transformation sequence.
All words have the same length.
All words contain only lowercase alphabetic characters.

Input Format:

The first argument of input contains a string, A.
The second argument of input contains a string, B.
The third argument of input contains an array of strings, C.

Output Format:

Return an integer representing the minimum number of steps required to change string A to string B.

Constraints:

1 <= length(A), length(B), length(C[i]) <= 25
1 <= length(C) <= 5e3

Example :

Input 1:
    A = "hit"
    B = "cog"
    C = ["hot", "dot", "dog", "lot", "log"]

Output 1:
    5

Explanation 1:
    "hit" -> "hot" -> "dot" -> "dog" -> "cog"