Count Of Distinct Palindromic Subsequences

medium
1. You are given a string.
2. You have to print the count of distinct and non-empty palindromic subsequences in the given string.
3. Two sequences s1 and s2 are distinct if here is some i, for which ith character in s1 and s2 are different.

Note -> String contains only lowercase letters.
          -> The answer will be in the integer range only.

Input Format

A String

Output Format

An Integer

Constraints

1 <= length of string <= 10000

Example

Input
bccb
Output
6
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