Balala Power!

Talented Mr.Tang has $n$ strings consisting of only lower case characters. He wants to charge them with Balala Power (he could change each character ranged from a to z into each number ranged from 0 to 25, but each two different characters should not be changed into the same number) so that he could calculate the sum of these strings as integers in base $26$ hilariously.

Mr.Tang wants you to maximize the summation. Notice that no string in this problem could have leading zeros except for string "0". It is guaranteed that at least one character does not appear at the beginning of any string.

The summation may be quite large, so you should output it in modulo $10^9 + 7$.

The input contains multiple test cases.

For each test case, the first line contains one positive integers $n$, the number of strings. $(1 \leq n \leq 100000)$

Each of the next $n$ lines contains a string $s_i$ consisting of only lower case letters. $(1 \leq |s_i| \leq 100000, \sum{|s_i|} \leq 10^6)$

For each test case, output "Case #$x$: $y$" in one line (without quotes), where $x$ indicates the case number starting from $1$ and $y$ denotes the answer of corresponding case.

1
a
2
aa
bb
3
a
ba
abc

Case #1: 25
Case #2: 1323
Case #3: 18221

2017 Multi-University Training Contest - Team 1