Sereja and Two Strings 2

Sereja has a string A consisting of n lower case English letters. Sereja calls two strings X and Y each of length n similar if they can be made equal by applying the following operation at most once in each of them. - Chose any two position i, j in the string (i can be equal to j too). Swap the characters at position i with character at position j. For example strings "abcd" and "acbd" are simi