write a go solution for Description:
A ticket is a non-empty string of digits from 1 to 9.

A lucky ticket is such a ticket that:

- it has an even length;
- the sum of digits in the first half is equal to the sum of digits in the second half.

You are given n ticket pieces s_1,s_2,...,s_n. How many pairs (i,j) (for 1<=i,j<=n) are there such that s_i+s_j is a lucky ticket? Note that it's possible that i=j.

Here, the + operator denotes the concatenation of the two strings. For example, if s_i is 13, and s_j is 37, then s_i+s_j is 1337.

Input Format:
The first line contains a single integer n (1<=n<=2*10^5) — the number of ticket pieces.

The second line contains n non-empty strings s_1,s_2,...,s_n, each of length at most 5 and consisting only of digits from 1 to 9.

Output Format:
Print a single integer — the number of pairs (i,j) (for 1<=i,j<=n) such that s_i+s_j is a lucky ticket.

Note:
None. Output only the code with no comments, explanation, or additional text.