[Hidden]

#### Description

After an amazing performance at World Finals, Timothy and Alex, who are no longer eligible for ICPC, have decided to look for a new challenge. They'd like to run for SGA President and Vice President. Unfortunately, they have realized that with tickets from the previous election such as Josh/Jad and Brad/Breon, they have no hope of winning because all winning tickets must have two
distinct names that start with the same first letter, so Timothy and Alex just won't do.

The Problem:
Given the names of each UCF student, calculate the number of possible President/Vice-President pairs who have a potential to win the SGA election.

#### Input

The first line of input contains a single positive integer, n (n ≤ 66,1831), representing the number of UCF students. The following n lines each contain a single first name of one UCF student. All names will consist of uppercase letters only and be between 1 and 20 letters long, inclusive. Each line represents a distinct student, but distinct students may have the same first name.

#### Output

On a line by itself, output the total number of President-Vice President pairs that have a chance to win the SGA election.

#### Samples

Input Copy
10
JOSH
JENNIFER
JENNIFER
JALEN
HASAAN
ALI
TIM
ALEX
TRAVIS
Output
22

#### Source

UCF2018
##### Problem Information

 Time Limit: 1000MS (C/C++,Others×2) Memory Limit: 128MB (C/C++,Others×2) Special Judge: No AC/Submit: 1 / 1 Tags:
##### Contests involved

 1036. UCF 2018