Palindrome pairs

3000ms

262144K

Description:

You are given a non-empty string s consisting of lowercase letters. Find the number of pairs of non-overlapping palindromic substrings of this string.

In a more formal way, you have to find the quantity of tuples (a, b, x, y) such that 1 ≤ a ≤ b < x ≤ y ≤ |s| and substrings s[a... b], s[x... y] are palindromes.

A palindrome is a string that can be read the same way from left to right and from right to left. For example, "abacaba", "z", "abba" are palindromes.

A substring s[i... j] (1 ≤ i ≤ j ≤ |s|) of string s = s₁s₂... s_|s| is a string s_is_i + 1... s_j. For example, substring s[2...4] of string s = "abacaba" equals "bac".

Input:

The first line of input contains a non-empty string s which consists of lowercase letters ('a'...'z'), s contains at most 2000 characters.

Output:

Output a single number — the quantity of pairs of non-overlapping palindromic substrings of s.

Please do not use the %lld format specifier to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d format specifier.

Sample Input:

aa

Sample Output:

Sample Input:

aaa

Sample Output:

Sample Input:

abacaba

Sample Output:

Informação

Provedor Codeforces

Código CF159D