B"A ticket is a non-empty string of digits from 1 to 9 . A lucky ticket is such a ticket that: 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. The first line contains a single integer n ( 1 <= n <= 2 cdot 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 . 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. "...