Problem:
Score : 300 points

Problem Statement

There are N people. The name of the i-th person is S_i.

We would like to choose three people so that the following conditions are met:

The name of every chosen person begins with M, A, R, C or H.

There are no multiple people whose names begin with the same letter.

How many such ways are there to choose three people, disregarding order?

Note that the answer may not fit into a 32-bit integer type.

Constraints

1 \leq N \leq 10^5

S_i consists of uppercase English letters.

1 \leq |S_i| \leq 10

S_i \neq S_j (i \neq j)

Input

Input is given from Standard Input in the following format:

N
S_1
:
S_N

Output

If there are x ways to choose three people so that the given conditions are met, print x.

Sample Input 1

5
MASHIKE
RUMOI
OBIRA
HABORO
HOROKANAI

Sample Output 1

2

We can choose three people with the following names:

MASHIKE, RUMOI, HABORO

MASHIKE, RUMOI, HOROKANAI

Thus, we have two ways.

Sample Input 2

4
ZZ
ZZZ
Z
ZZZZZZZZZZ

Sample Output 2

0

Note that there may be no ways to choose three people so that the given conditions are met.

Sample Input 3

5
CHOKUDAI
RNG
MAKOTO
AOKI
RINGO

Sample Output 3

7

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
import java.io.*;

public class Main{

	public static void main(String[] args) throws IOException {
		long arr[] = new long[5]; int N = readInt(); for(int i = 1; i<=N; i++) {
			String s = next();
			if(s.charAt(0) == 'M') arr[0]++; if(s.charAt(0) == 'A') arr[1]++;
			if(s.charAt(0) == 'R') arr[2]++; if(s.charAt(0) == 'C') arr[3]++; if(s.charAt(0) == 'H') arr[4]++;
		}
		
		long ans = 0;
		for(int i = 0; i<5; i++) for(int j = i+1; j<5; j++) for(int k = j+1; k<5; k++) ans += arr[i]*arr[j]*arr[k]; println(ans);
		exit();
	}

	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	static StringTokenizer st;

	static String next() throws IOException {
		while (st == null || !st.hasMoreTokens())
			st = new StringTokenizer(br.readLine().trim());
		return st.nextToken();
	}

	static long readLong() throws IOException {
		return Long.parseLong(next());
	}

	static float readFloat() throws IOException {
		return Float.parseFloat(next());
	}

	static boolean readBoolean() throws IOException {
		return Boolean.parseBoolean(next());
	}

	static short readShort() throws IOException {
		return Short.parseShort(next());
	}

	static byte readByte() throws IOException {
		return Byte.parseByte(next());
	}

	static int readInt() throws IOException {
		return Integer.parseInt(next());
	}

	static double readDouble() throws IOException {
		return Double.parseDouble(next());
	}

	static char readCharacter() throws IOException {
		return next().charAt(0);
	}

	static String readLine() throws IOException {
		return br.readLine().trim();
	}

	static PrintWriter pr = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

	static void print(Object o) {
		pr.print(o);
	}

	static void println(Object o) {
		pr.println(o);
	}

	static void flush() {
		pr.flush();
	}

	static void println() {
		pr.println();
	}

	static void exit() throws IOException {
		br.close();
		pr.close();
		System.exit(0);
	}
}