Minimum Rotations to Transform String

You are given two strings S and T of length n. In a single operation, you can remove the first character of S and append it to the end of S (a rotation). Your task is to determine the minimum number of such operations required to transform S into T. If it is impossible to transform S into T using these operations, output -1.

More formally, find the minimum non-negative integer i such that

where S[i:] denotes the substring of S starting from the i-th character (0-indexed) and S[:i] denotes the substring of S before the i-th character. If no such i exists, print -1.

Note: It is necessary that both strings have the same multiset of characters for a valid transformation to exist.

inputFormat

The input consists of three lines:

• The first line contains an integer n representing the length of the strings.
• The second line contains the string S.
• The third line contains the string T.

outputFormat

Output a single integer which is the minimum number of operations required to transform S into T. If it is impossible, output -1.

5
abcde
cdeab

2