March

AtCoder

IDabc089_c

Time2000ms

Memory256MB

Difficulty—

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: $N$ $S_1$ $:$ $S_N$ [samples]

Samples

Input #1

5
MASHIKE
RUMOI
OBIRA
HABORO
HOROKANAI

Output #1

2

We can choose three people with the following names:

*   `MASHIKE`, `RUMOI`, `HABORO`
    
*   `MASHIKE`, `RUMOI`, `HOROKANAI`
    

Thus, we have two ways.

Input #2

4
ZZ
ZZZ
Z
ZZZZZZZZZZ

Output #2

0

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

Input #3

5
CHOKUDAI
RNG
MAKOTO
AOKI
RINGO

Output #3

API Response (JSON)

{
  "problem": {
    "name": "March",
    "description": {
      "content": "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`,",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc089_c"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "There are $N$ people. The name of the $i$\\-th person is $S_i$.\nWe would like to choose three people so that the following conditions are met:\n\n*   The name of every chosen person begins with `M`, `A`,...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments