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



Sample input:
5
MASHIKE
RUMOI
OBIRA
HABORO
HOROKANAI


Sample output:
2

Submission status: Accepted

Solution code:
def main():
    from collections import Counter
    from itertools import combinations

    n, *s = map(lambda x: str(x)[0], open(0).read().split())
    c = Counter(s)

    m = [c.get(x) if c.get(x) != None else 0 for x in ["M", "A", "R", "C", "H"]]
    ans = sum(i * j * k for (i, j, k) in combinations(m, 3))
    print(ans)


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
def main():
    from collections import Counter
    from itertools import combinations

    n, *s = map(lambda x: str(x)[0], open(0).read().split())
    c = Counter(s)

    m = [c.get(x) if c.get(x) != None else 0 for x in ["M", "A", "R", "C", "H"]]
    ans = 0
    if len(m) >= 3:
        for (i, j, k) in combinations(m, 3):
            ans += i * j * k

    print(ans)


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
def main():
    from collections import Counter
    from itertools import combinations

    n, *s = map(lambda x: str(x)[0], open(0).read().split())
    c = Counter(s)

    m = [v for k, v in c.items() if k in ["M", "A", "R", "C", "H"]]
    ans = 0
    if len(m) >= 3:
        for (i, j, k) in combinations(m, 3):
            ans += i * j * k

    print(ans)


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
import itertools

N = int(input())
count = {c: 0 for c in ['M', 'A', 'R', 'C', 'H']}

for _ in range(N):
    S = input()
    if S[0] in ['M', 'A', 'R', 'C', 'H']:
        count[S[0]] += 1

num = [count[c] for c in count]
ans = 0
for v in itertools.combinations(num, 3):
    ans += (v[0] * v[1] * v[2])
print(ans)

Submission status: Accepted

Solution code:
n = int(input())
# n, k = list(map(int, input().split()))
#a = list(map(int, input().split()))
# abc = [int(input()) for i in range(5)]
march = {"M": 0, "A": 0, "R": 0, "C": 0, "H": 0}
for i in range(n):
    s = input()
    if s[0] in "MARCH":
        march[s[0]] += 1

total = 0
total += march["M"]*march["R"]*march["A"]
total += march["M"]*march["A"]*march["C"]
total += march["M"]*march["A"]*march["H"]
total += march["M"]*march["R"]*march["C"]
total += march["M"]*march["R"]*march["H"]
total += march["A"]*march["R"]*march["C"]
total += march["A"]*march["C"]*march["H"]
total += march["R"]*march["C"]*march["H"]
total += march["C"]*march["H"]*march["M"]
total += march["A"]*march["R"]*march["H"]

print(total)

Submission status: Accepted

Solution code:
from collections import deque,Counter
from itertools import permutations,combinations,combinations_with_replacement

N = int(input())
rows = [input()[0] for _ in range(N)]

cnt = Counter(rows)

ans = 0
for k in combinations(["M","A","R","C","H"],3):
    ans += cnt[k[0]]*cnt[k[1]]*cnt[k[2]]

print(ans)

Submission status: Accepted

Solution code:
from sys import stdin
import itertools
def main():
    #入力
    readline=stdin.readline
    N=int(readline())
    MARCH=[0,0,0,0,0]
    M=0
    A=1
    R=2
    C=3
    H=4
    for _ in range(N):
        S=readline().strip()
        if S[0]=="M":
            MARCH[M]+=1
        elif S[0]=="A":
            MARCH[A]+=1
        elif S[0]=="R":
            MARCH[R]+=1
        elif S[0]=="C":
            MARCH[C]+=1
        elif S[0]=="H":
            MARCH[H]+=1

    seq=[M,A,R,C,H]
    coms=itertools.combinations(seq,3)
    res=0
    for li in coms:
        X=li[0]
        Y=li[1]
        Z=li[2]
        res+=MARCH[X]*MARCH[Y]*MARCH[Z]

    print(res)
    
if __name__=="__main__":
    main()

Submission status: Accepted

Solution code:
from itertools import combinations
n = int(input())
s = []
for _ in range(n):
    s.append(input())

march = {'M':0, 'A':0, 'R':0, 'C':0, 'H':0}
for i in s:
    if i[0] in march:
        march[i[0]] += 1

ans = 0
for i, j, k in combinations(march.values(), 3):
    ans += i*j*k
print(ans)

Submission status: Accepted

Solution code:
N=int(input())
s=[]
for i in range(N):
  S=input()
  s.append(S)
m=0
a=0
r=0
c=0
h=0
for i in range(N):
  if s[i][0]=="M":
    m+=1
  if s[i][0]=="A":
    a+=1
  if s[i][0]=="R":
    r+=1
  if s[i][0]=="C":
    c+=1
  if s[i][0]=="H":
    h+=1
print(m*a*r+m*a*c+m*a*h+m*r*c+m*r*h+m*c*h+a*r*c+a*r*h+a*c*h+r*c*h)

Submission status: Accepted

Solution code:
import itertools
def main():
    N = int(input())
    initial = {"M" : 0, "A" : 0, "R" : 0, "C" : 0, "H" : 0}

    for i in range(N):
        S = input()
        if S[0] == "M" or S[0] == "A" or S[0] == "R" or S[0] == "C" or S[0] == "H":
            initial[S[0]] += 1
    pat = 0

    for c in itertools.combinations("MARCH", 3):
        pat += initial[c[0]]*initial[c[1]]*initial[c[2]]
        
    print(pat)
if __name__ == "__main__":
    main()

Submission status: Accepted

Solution code:
n = int(input())
dict1 = {}
li = ['M', 'A', 'R', 'C', 'H']
ans = 0

for _ in range(n):
    s = input()
    if s[0] not in dict1:
        dict1[s[0]] = 1
    else:
        dict1[s[0]] += 1

for i in range(5):
    for j in range(i+1, 5):
        for k in range(j+1, 5):
            if li[i] in dict1 and li[j] in dict1 and li[k] in dict1:
                ans += dict1[li[i]] * dict1[li[j]] * dict1[li[k]]

print(ans)

Submission status: Accepted

Solution code:
from itertools import permutations, combinations,combinations_with_replacement,product

n = int(input())
p = [0 for i in range(5)]

for i in range(n):
    kar = input()
    if kar[0] == "M":
        p[0] += 1
    elif kar[0] == "A":
        p[1] += 1
    elif kar[0] == "R":
        p[2] += 1
    elif kar[0] == "C":
        p[3] += 1
    elif kar[0] == "H":
        p[4] += 1

a=[0,1,2,3,4]

tyu = list(combinations(a,3))
ans = 0
for x , y , z in tyu:
    ans += p[x]*p[y]*p[z]
print(ans)

Submission status: Accepted

Solution code:
n=int(input())
l=[0]*5
for i in range(n):
    s=input()
    if s[0]=='M':
        l[0]+=1
    elif s[0]=='A':
        l[1]+=1
    elif s[0]=='R':
        l[2]+=1
    elif s[0]=='C':
        l[3]+=1
    elif s[0]=='H':
        l[4]+=1
k0=l[0]*(l[1]*(l[2]+l[3]+l[4])+l[2]*(l[3]+l[4])+l[3]*l[4])
k1=l[1]*(l[2]*(l[3]+l[4])+l[3]*l[4])
k2=l[2]*l[3]*l[4]
print(k0+k1+k2)

Submission status: Accepted

Solution code:
N = int(input())
num = [0 for _ in range(5)]
for _ in range(N):
    s = input()[0]
    if s == "M":
        num[0] += 1
    elif s == "A":
        num[1] += 1
    elif s == "R":
        num[2] += 1
    elif s == "C":
        num[3] += 1
    elif s == "H":
        num[4] += 1
ans = 0
for i in range(0, 3):
    for j in range(i + 1, 4):
        for k in range(j + 1, 5):
            ans += num[i] * num[j] * num[k]
print(ans)

Submission status: Accepted

Solution code:
n=int(input())
march=[0,0,0,0,0]
for i in range(n):
  s=input()
  if s[0]=="M":
    march[0]+=1
  elif s[0]=="A":
    march[1]+=1
  elif s[0]=="R":
    march[2]+=1
  elif s[0]=="C":
    march[3]+=1
  elif s[0]=="H":
    march[4]+=1
finalans=0
for i in range(2**5):
  ans=1
  count=0
  for j in range(5):
    if ((i>>j)&1):
      ans*=march[j]
      count+=1
  if count!=3:
    ans=0
  finalans+=ans
print(finalans)

Submission status: Accepted

Solution code:
from collections import Counter
from itertools import combinations
N = int(input())

S = [input()[0] for _ in range(N)]

s = Counter(S)

sd = {'M':0, 'A':0, 'R':0, 'C':0, 'H':0}

for i in 'MARCH':
    sd[i] += s[i]
    
ans = 0

for ss in combinations(['M','A','R','C','H'], 3):
    ans += sd[ss[0]]*sd[ss[1]]*sd[ss[2]]
    
print(ans)

Submission status: Accepted

Solution code:
n = int(input())
m = "MARCH"
l = {}
cnt = 0
for _ in range(n):
    init = input()[0]
    if init not in m:
        continue
    if init not in l:
        cnt += 1
        l[init] = 0
    l[init] += 1
if cnt <= 2:
    print(0)
    exit()
l = list(l.values())
n = len(l)
ans = 0
for i in range(n-2):
    for j in range(i+1, n-1):
        for k in range(j+1, n):
            ans += l[i] * l[j] * l[k]
print(ans)

Submission status: Accepted

Solution code:
n = int(input())
import collections
import itertools
wo = ["M","A","R","C","H"]
co = collections.Counter()
for i in range(n):
    s = input()
    if s[0] in wo:
        co[s[0]] +=1
ans = 0
for c in itertools.combinations(wo,3):
    tmp =1
    for w in c:
        tmp*=co[w]
    ans+=tmp
print(ans)

Submission status: Accepted

Solution code:
# coding: utf-8
# Your code here!
n=int(input())
s=[]
for i in range(n):
    s.append(input())
t=[0]*5
#print(s)

for i in range(n):
    c=list(s[i])
    if c[0]=='M':
        t[0]+=1
    if c[0]=='A':
        t[1]+=1
    if c[0]=='R':
        t[2]+=1
    if c[0]=='C':
        t[3]+=1
    if c[0]=='H':
        t[4]+=1
    #print(c)
ans=0
cnt=1
#print(t)
for i in range(3):
    for j in range(i+1,4):
        for k in range(j+1,5):
                cnt=t[k]*t[j]*t[i]
                ans+=cnt
print(ans)

Submission status: Accepted

Solution code:
N=int(input())
S=[input() for i in range(N)]
m,a,r,c,h = 0,0,0,0,0
for s in S:
  if 'M' == s[0]:
    m+=1
  elif 'A' == s[0]:
    a+=1
  elif 'R' == s[0]:
    r+=1
  elif 'C' == s[0]:
    c+=1
  elif 'H' == s[0]:
    h+=1

print(m*a*r + m*a*c + m*a*h + m*r*c + m*r*h + m*c*h + a*r*c + a*r*h + a*c*h + r*c*h)

Submission status: Accepted

Solution code:
def bit_make(n,m):
    s = [list(map(int,bin(x)[2:].zfill(n))) for x in range(2**n)]
    s2 = []
    for i in range(2**n):
        if sum(s[i])==m:
            s2.append(s[i])
    return s2

n = int(input())
march = [0]*5
c = [0]*5
ans = 0
for i in range(n):
    s = input()
    if s[0] == 'M':
        march[0]+=1
        c[0]=1
    if s[0] == 'A':
        march[1]+=1
        c[1]=1
    if s[0] == 'R':
        march[2]+=1
        c[2]=1
    if s[0] == 'C':
        march[3]+=1
        c[3]=1
    if s[0] == 'H':
        march[4]+=1
        c[4]=1
m = sum(c)
march.sort(reverse = True)
x = bit_make(m,3)
ans1 = 1
for i in range(len(x)):
    for j in range(m):
        if x[i][j]==1:
            ans1*=march[j]*x[i][j]
    ans+=ans1
    ans1=1

print(ans)

Submission status: Accepted

Solution code:
from collections import Counter
import itertools
N = int(input())
S = [input()[0] for _ in range(N)]

counter = Counter(S)
answer = 0
for x,y,z in itertools.combinations('MARCH',3):
  answer += counter[x] * counter[y] * counter[z]

print(answer)

Submission status: Accepted

Solution code:
N = int(input())
dic = {"M": 0, "A": 0, "R": 0, "C": 0, "H": 0}
p = ["M", "M", "M", "M", "M", "M", "A", "A", "A", "R"]
q = ["A", "R", "C", "A", "R", "A", "R", "R", "C", "C"]
r = ["R", "C", "H", "C", "H", "H", "C", "H", "H", "H"]


for _ in range(N):
    s = input()
    if s[0] in "MARCH":
        dic[s[0]] += 1

res = 0
for i in range(10):
    res += dic[p[i]] * dic[q[i]] * dic[r[i]]

print(res)

Submission status: Accepted

Solution code:
n = int(input())
dic = {'M':set(),'A':set(),'R':set(),'C':set(),'H':set()}
for i in range(n):
    s = input()
    if s[0] in dic.keys():
        dic[s[0]].add(s)

ans = 0

M = len(dic['M'])
A = len(dic['A'])
R = len(dic['R'])
C = len(dic['C'])
H = len(dic['H'])

memo =[[M, A, R],[M, A ,C],[M, A, H],[M, R, C],[M, R, H],[M, C, H],[A, R, C],[A, R, H],[A,C,H],[R, C, H]]
for i in memo:
    ans += (i[0]*i[1]*i[2])
    
    
print(ans)

Submission status: Accepted

Solution code:
n = int(input())

counts = [0] * 5
for i in range(n):
    name = input()
    
    if name[0] == 'M':
        counts[0] += 1
    elif name[0] == 'A':
        counts[1] += 1
    elif name[0] == 'R':
        counts[2] += 1
    elif name[0] == 'C':
        counts[3] += 1
    elif name[0] == 'H':
        counts[4] += 1
 
ans = 0       
for i in range(5):
    for j in range(5):
        for k in range(5):
            if i == j or j == k or k == i:
                continue
            
            #print(i, j, k, ':', counts[i], counts[j], counts[k])
            ans += counts[i] * counts[j] * counts[k]

print(ans // 6)

Submission status: Accepted

Solution code:
N = int(input())
listA = []
listB = []
d = ["M","A","R","C","H"]
ans = 0
for i in range(N):
    listA.append(input()[0])
for i in d:
    listB.append(listA.count(i))
listB = list(map(int,listB))
listB = [i for i in listB if i != 0]
length = len(listB)
if length < 3:
    print(0)
    exit()
total = 0
for i in range(length-2):
    for j in range(i+1,length):
        for k in range(j+1,length):
            total += listB[i] * listB[j] * listB[k]
            pass
print(total)

Submission status: Accepted

Solution code:
import itertools
n = int(input())
ans = 0
cnt = { "M": 0, "A": 0, "R": 0, "C": 0, "H": 0}
for i in range(n):
    s = input()
    if s[0] in cnt:
        cnt[s[0]] += 1
c = itertools.combinations("MARCH", 3)
for i, j, k in c:
    ans += cnt[i] * cnt[j] * cnt[k]
print(ans)

Submission status: Accepted

Solution code:
n=int(input())
m=0
a=0
r=0
c=0
h=0

for i in range(n):
    s=input()
    if s[0]=="M":
        m+=1
    elif s[0]=="A":
        a+=1        
    elif s[0]=="R":
        r+=1        
    elif s[0]=="C":
        c+=1        
    elif s[0]=="H":
        h+=1

d=[0]*5
d[0]=m
d[1]=a
d[2]=r
d[3]=c
d[4]=h

import itertools
dsum=0
for i in itertools.combinations(range(5), 3):
    dsum=dsum+d[i[0]]*d[i[1]]*d[i[2]]
print(dsum)

Submission status: Accepted

Solution code:
from itertools import combinations

n = int(input())
set_m = set()
set_a = set()
set_r = set()
set_c = set()
set_h = set()
for i in range(n):
    s = input()
    start = s[0]
    if start == 'M':
        set_m.add(s)
    elif start == 'A':
        set_a.add(s)
    elif start == 'R':
        set_r.add(s)
    elif start == 'C':
        set_c.add(s)
    elif start == 'H':
        set_h.add(s)
sets = [set_m, set_a, set_r, set_c, set_h]
numbers = []
for se in sets:
    if len(se) > 0:
        numbers.append(len(se))
num_group = len(numbers)
if num_group < 3:
    ans = 0
else:
    ans = 0
    ind_ls = list(range(num_group))
    c = combinations(ind_ls, 3)
    for ind1, ind2, ind3 in c:
        ans += numbers[ind1] * numbers[ind2]* numbers[ind3]
print(ans)

Submission status: Accepted

Solution code:
n = int(input())
S = [input() for i in range(n)]

d = {}
for s in S:
    c = s[0]
    if c not in 'MARCH': continue
    if c in d:
        d[c]+=1
    else:
        d[c] = 1

if len(d) <= 2:
    print(0)
    exit()

d_list = list(d.values());
n = len(d_list)
ans = 0
for i in range(n):
    for j in range(i+1, n):
        for k in range(j+1, n):
            ans += d_list[i] * d_list[j] * d_list[k]

print(ans)

Submission status: Accepted

Solution code:
n=int(input())
p=[]
for i in range(n):
  s=input()
  p.append(s[0])
m=p.count("M")
a=p.count("A")
r=p.count("R")
c=p.count("C")
h=p.count("H")
print(m*a*r+m*a*h+m*a*c+m*r*c+m*r*h+m*c*h+a*r*c+a*r*h+a*c*h+r*c*h)

Submission status: Accepted

Solution code:
import sys

args = []

for l in sys.stdin:
  args.append(l.strip('\n'))
  
names = args[1:]

focus_initial = 'MARCH'
initial_num = [0, 0, 0, 0, 0]
for name in names:
  for i in range(5):
    if focus_initial[i] == name[0]:
      initial_num[i] += 1
      
ct = 0
for i in range(5):
  for j in range(i+1, 5):
    for k in range(j+1, 5):
      ct += initial_num[i] * initial_num[j] * initial_num[k]

print(ct)

Submission status: Accepted

Solution code:
import collections
import itertools
n = int(input())
li = []
for i in range(n):
    li.append(input()[0])

c = collections.Counter(li)
c_li = [c['M'],c['A'],c['R'],c['C'],c['H']]
#print(li,c,c_li)

count = 0
combination = list(itertools.combinations([0,1, 2, 3,4], 3))
for co in combination:
    tmp = 1
    for c in co:
        if c_li[c] == 0:
            tmp = 0
            break
        tmp *= c_li[c]
    count += tmp
print(count)

Submission status: Accepted

Solution code:
from itertools import combinations

N = int(input())
march = list('MARCH')
name = {x: 0 for x in march}
for _ in range(N):
    s = input()
    if s[0] in march:
        name[s[0]] += 1
ans = 0
for a, b, c in combinations(name.values(), 3):
    ans += a*b*c
print(ans)

Submission status: Accepted

Solution code:
from collections import defaultdict
from itertools import combinations

n = int(input())
d = defaultdict(int)

for _ in range(n):
    s = input()
    if s[0] == 'M':
        d['M'] += 1
    if s[0] == 'A':
        d['A'] += 1
    if s[0] == 'R':
        d['R'] += 1
    if s[0] == 'C':
        d['C'] += 1
    if s[0] == 'H':
        d['H'] += 1

ls = [dd for dd in d]

if len(ls) < 3:
    print(0)
    exit()

ans = 0
for v in combinations(ls, 3):
    cnt = 1
    for vv in v:
        cnt *= d[vv]
    ans += cnt

print(ans)

Submission status: Accepted

Solution code:
import sys
readline = sys.stdin.readline

def main():
    N = int(input())
    cnt = [0, 0, 0, 0, 0]
    for _ in range(N):
        s = input()
        if s[0] == 'M':
            cnt[0] += 1
        elif s[0] == 'A':
            cnt[1] += 1
        elif s[0] == 'R':
            cnt[2] += 1
        elif s[0] == 'C':
            cnt[3] += 1
        elif s[0] == 'H':
            cnt[4] += 1
    
    ans = 0
    for i in range(5):
        for j in range(i+1, 5):
            for k in range(j+1, 5):
                ans += cnt[i] * cnt[j] * cnt[k]
    
    print(ans)


if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
import collections
import itertools
n = int(input())
s = []
for i in range(n):
    a = list(input())
    s.append(a[0])

c = collections.Counter(s)
select_s = ['M', 'A', 'R', 'C', 'H']
ans = 0
for select in itertools.combinations(select_s, 3):
    ans += c[select[0]] * c[select[1]] * c[select[2]]
print(ans)

Submission status: Accepted

Solution code:
n = int(input())
dic = {}
ss = ['M','A','R','C','H']
for i in range(n):
    s = input()
    if s[0] in ss:
        if s[0] not in dic :
            dic[s[0]] = 0
        dic[s[0]] += 1

from itertools import combinations
key = list(dic.keys())

klist = list(combinations(key,3))
#print(klist)

ans = 0
for i in range(len(klist)):
    ans += dic[klist[i][0]]*dic[klist[i][1]]*dic[klist[i][2]]

print(ans)

Submission status: Accepted

Solution code:
N=int(input())
S=[input() for _ in range(N)]

MARCH=[0]*5
for i in range(N):
  if S[i][0]=="M":
    MARCH[0]+=1
  elif S[i][0]=="A":
    MARCH[1]+=1
  elif S[i][0]=="R":
    MARCH[2]+=1
  elif S[i][0]=="C":
    MARCH[3]+=1
  elif S[i][0]=="H":
    MARCH[4]+=1

ans=0
for i in range(3):
  for j in range(i+1,4):
    for k in range(j+1,5):
      ans+=MARCH[i]*MARCH[j]*MARCH[k]
print(ans)

Submission status: Accepted

Solution code:
# solution

import io
import sys
from itertools import combinations as comb

n, *S = open(0).read().split()

s = [i[0] for i in S]

array = [s.count(i) for i in 'MARCH']

ret = sum(x * y * z for x, y, z in comb(array, 3))

print(ret)

Submission status: Accepted

Solution code:
N = int(input())
pref = 'MARCH'
D = {}
for _ in range(N):
    s = input()
    if s[0] in pref:
        if s[0] in D:
            D[s[0]] += 1
        else:
            D[s[0]] = 1

lst = list(D.keys())
if len(lst) < 3:
    print(0)
    exit()
ans = 0
for i in range(len(lst)-2):
    for j in range(i+1, len(lst)-1):
        for k in range(j+1, len(lst)):
            ans += D[lst[i]] * D[lst[j]] * D[lst[k]]

print(ans)

Submission status: Accepted

Solution code:
N=int(input())
S=[input() for _ in range(N)]

MARCH=[0]*5
for i in range(N):
  if S[i][0]=="M":
    MARCH[0]+=1
  elif S[i][0]=="A":
    MARCH[1]+=1
  elif S[i][0]=="R":
    MARCH[2]+=1
  elif S[i][0]=="C":
    MARCH[3]+=1
  elif S[i][0]=="H":
    MARCH[4]+=1

ans=0
for i in range(3):
  for j in range(i+1,4):
    for k in range(j+1,5):
      ans+=MARCH[i]*MARCH[j]*MARCH[k]
print(ans)

Submission status: Accepted

Solution code:
import itertools

n=int(input())
li=[]

for i in range(n):
    li.append(input()[0])

tm=list(itertools.combinations(["M","A","R","C","H"],3))
ans=0

for j1,j2,j3 in tm:
    ans+=li.count(j1)*li.count(j2)*li.count(j3)

print(ans)

Submission status: Accepted

Solution code:
import itertools
*s, = open(0)
print(sum(i*j*k for i,j,k in itertools.combinations([sum(t.startswith(l) for t in s) for l in "MARCH"], 3)))

Submission status: Accepted

Solution code:
import itertools

N = int(input())

d = {'M':0, 'A':0, 'R':0, 'C':0, 'H':0}

for i in range(N):
    s = input()
    if s[0] in d:
        d[s[0]] += 1

c = itertools.combinations('MARCH', 3)

ans = 0

for i, j, k in c:
    ans += d[i]*d[j]*d[k]

print(ans)

Submission status: Accepted

Solution code:
n = int(input())
m, a, r, c, h = 0, 0, 0, 0, 0
for i in range(n):
  s = input()
  if s[0] == 'M':
    m += 1
  elif s[0] == 'A':
    a += 1
  elif s[0] == 'R':
    r += 1
  elif s[0] == 'C':
    c += 1
  elif s[0] == 'H':
    h += 1
total = m + a + r + c + h
res = m * a * r + m * a * c + m * a * h + m * r * c + m * r * h + m * c * h + a * r * c + a * r * h + a * c * h + r * c * h

print(res)

Submission status: Accepted

Solution code:
N = int(input())
d = {'M':0, 'A':0, 'R':0, 'C':0, 'H':0}
for _ in range(N):
    S = input()
    if S[0] in d:
        d[S[0]] += 1
L = ['M', 'A', 'R', 'C', 'H']
ans = 0
for i in range(3):
    for j in range(i+1, 4):
        for k in range(j+1, 5):
            ans += d[L[i]] * d[L[j]] * d[L[k]]
print(ans)

Submission status: Accepted

Solution code:
import sys
## io
IS = lambda: sys.stdin.readline().rstrip()
II = lambda: int(IS())
MII = lambda: list(map(int, IS().split()))
MIIZ = lambda: list(map(lambda x: x-1, MII()))
## dp
INIT_VAL = 0
DP2 = lambda d1, d2: [[INIT_VAL]*d2 for _ in range(d1)]
DP3 = lambda d1, d2, d3: [[[INIT_VAL]*d3 for _ in range(d2)] for _ in range(d1)]

from itertools import combinations

def main():
    n = II()
    initials = ['M', 'A', 'R', 'C', 'H']
    names = {name: [] for name in initials}
    for i in range(n):
        s = IS()
        if not s[0] in initials: continue
        names[s[0]].append(s)
    cnt = 0
    for a,b,c in combinations(initials, 3):
        cnt += len(names[a])*len(names[b])*len(names[c])
    print(cnt)

if __name__ == '__main__':
    main()

Submission status: Accepted

Solution code:
import itertools
N = int(input())
S = [input() for _ in range(N)]
march = ['M', 'A', 'R', 'C', 'H']
cnt = [0]*5
for s in S:
    if s[0] == 'M':
        cnt[0] += 1
    elif s[0] == 'A':
        cnt[1] += 1
    elif s[0] == 'R':
        cnt[2] += 1
    elif s[0] == 'C':
        cnt[3] += 1
    elif s[0] == 'H':
        cnt[4] += 1
ans = 0
for comb in itertools.combinations(cnt, 3):
    ans += comb[0]*comb[1]*comb[2]
print(ans)

Submission status: Accepted

Solution code:
#from statistics import median
#import collections
#aa = collections.Counter(a) # list to list || .most_common(2)で最大の2個とりだせるお a[0][0]
#from itertools import combinations # (string,3) 3回
#from collections import deque
#import collections.defaultdict(list)
#import bisect
#
#
# pythonで無理なときは、pypyでやると正解するかも！！
#
#

mod = 10**9 + 7

def readInts():
  return list(map(int,input().split()))
def main():
    # 選ぶ3人の頭文字がどうなっているかというと、'M','A','R'や、'A','C','H'のように、
    # 'MARCH'の中から選べる"異なる"3文字となっている
    # たとえば頭文字'M','A','R' に絞って考えると、 それぞれの文字で始まる人が、
    # 5,9,4人だった場合、組み合わせの数は 5 * 9 * 4 = 180 となる
    # これをすべて異なる3文字の組み合わせで調べ上げて、足し合わす。
    # ただし、各頭文字で始まる人がいなかった場合に、Keyerrorに注意

    # Python では ある頭文字で始まる人が何人いるかは、
    # collections.Counterを使って数え上げられる。
    # また、5個の中から異なる3個を取る組み合わせの列挙は、
    # itertools.combinationsを使える
    from collections import Counter
    from itertools import combinations

    n = int(input())
    l = [input()[0] for _ in range(n)]
    lc = Counter(l) # これで数えれる
    #print(lc)
    #     5
    # MASHIKE
    # RUMOI
    # OBIRA
    # HABORO
    # HOROKANAI
    # Counter({'H': 2, 'M': 1, 'R': 1, 'O': 1})

    con = []
    for c in 'MARCH': # ここ文字列でもいけるんだ
        if c in lc:
            con.append(lc[c]) # 辞書登録してるね。
            # ここで、conリスト　に 頭文字の個数を入れる。
    ans = 0
    for a,b,c in combinations(con,3): # conリストにある全通りの組み合わせを試す。
        ans += a * b * c
    print(ans)

if __name__ == '__main__':
  main()

Submission status: Accepted

Solution code:
n = int(input())
s = []
for i in range(n):
    s.append(input())
s = sorted(s)
m = 0
a = 0
r = 0
c = 0
h = 0
for i in range(n):
    x = s[i]
    if x[0]=='M': m+=1
    elif x[0]=='A': a+=1
    elif x[0]=='R': r+=1
    elif x[0]=='C': c+=1
    elif x[0]=='H': h+=1
ans = m*a*r+m*a*c+m*a*h+m*r*c+m*r*h+m*c*h+a*r*c+a*r*h+a*c*h+r*c*h
print(ans)

Submission status: Accepted

Solution code:
def main():
    from collections import defaultdict
    from itertools import combinations

    N = int(input())

    d = defaultdict(int)
    for i in range(N):
        s = input()
        d[s[0]] += 1

    ans = 0
    for comb in combinations('MARCH', r=3):
        t = 1
        for char in comb:
            t *= d[char]
        ans += t
    print(ans)


if __name__ == '__main__':
    main()

# import sys
#
# sys.setrecursionlimit(10 ** 7)
#
# input = sys.stdin.readline
# rstrip()
# int(input())
# map(int, input().split())

Submission status: Accepted

Solution code:
N=int(input())

name_dic={}
for i in range(N):
  S=input()
  if S[0]!="M" and S[0]!="A" and S[0]!="R" and S[0]!="C" and S[0]!="H":
    continue
  
  if S[0] in name_dic:
    name_dic[S[0]]+=1
  else:
    name_dic[S[0]]=1
#print(name_dic)

name_list=list(name_dic.values())
#print(name_list)
answer=0
for i in range(len(name_list)):
  for j in range(i+1,len(name_list)):
    for k in range(j+1,len(name_list)):
      answer+=name_list[i]*name_list[j]*name_list[k]

print(answer)

Submission status: Accepted

Solution code:
N = int(input())
S = [0] * 5
for _ in range(N):
  s = input()
  if s[0] == "M": S[0] += 1
  elif s[0] == "A": S[1] += 1
  elif s[0] == "R": S[2] += 1
  elif s[0] == "C": S[3] += 1
  elif s[0] == "H": S[4] += 1
 
import itertools
ans = 0
for v in itertools.combinations(S, 3):
  ans +=  v[0] * v[1] * v[2]
print(ans)

Submission status: Accepted

Solution code:
n=int(input())
s=[]
l=['M','A','R','C','H']
d={'M':0,'A':0,'R':0,'C':0,'H':0}
for _ in range(n):
  s_=input()
  if s_[0] in l:
    d[s_[0]]+=1
ans=0
for i in range(3):
  for j in range(i+1,4):
    for k in range(j+1,5):
      ans+=d[l[i]]*d[l[j]]*d[l[k]]
print(ans)

Submission status: Accepted

Solution code:
N=int(input())
m=0
a=0
r=0
c=0
h=0
for i in range(N):
  s=input()
  if s[0]=="M":
    m+=1
  if s[0]=="A":
    a+=1
  if s[0]=="R":
    r+=1
  if s[0]=="C":
    c+=1
  if s[0]=="H":
    h+=1
ans=0
L=[m,a,r,c,h]
for i in range(3):
  for j in range(i+1,4):
    for k in range(j+1,5):
      ans+=L[i]*L[j]*L[k]
print(ans)

Submission status: Accepted

Solution code:
N = int(input())
S = [list(input()) for _ in range(N)]
san = [0]*5
san[0] = sum([S[i1][0]=="M" for i1 in range(N)])
san[1] = sum([S[i2][0]=="A" for i2 in range(N)])
san[2] = sum([S[i3][0]=="R" for i3 in range(N)])
san[3] = sum([S[i4][0]=="C" for i4 in range(N)])
san[4] = sum([S[i5][0]=="H" for i5 in range(N)])

ans = 0
for i in range(3):
    for j in range(i+1,4):
        for k in range(j+1, 5):
            ans += san[i]*san[j]*san[k]
print(ans)

Submission status: Accepted

Solution code:
n=int(input())
a=[0,0,0,0,0]
for i in range(n):
    b=input()[0]
    if b=='M':
        a[0]+=1
    if b=='A':
        a[1]+=1
    if b=='R':
        a[2]+=1
    if b=='C':
        a[3]+=1
    if b=='H':
        a[4]+=1
b=0
for i in range(5):
    for j in range(i+1,5):
        for k in range(j+1,5):
            b+=a[i]*a[j]*a[k]
print(b)

Submission status: Accepted

Solution code:
N = int(input())
s = [input() for _ in range(N)]
count = [0]*5
for i in s:
    if i[0]=="M":
        count[0] += 1
    elif i[0]=="A":
        count[1] += 1
    elif i[0]=="R":
        count[2] += 1
    elif i[0]=="C":
        count[3] += 1
    elif i[0]=="H":
        count[4] += 1
ans = 1
i = 0
h = len(count)
while i < h:
    if count[i]==0:
        count.pop(i)
        h -= 1
        i = 0
    else:
        i += 1

if len(count)<3:
    ans = 0
elif len(count)==3:
    ans = 1
    for i in count:
        ans *=  i
else:
    ans = 0
    for bit in range(1<<len(count)):
        a = []
        b = 1
        for i in range(len(count)):
            mask = 1<<i
            if mask&bit:
                a.append(count[i])
                b *= count[i] 
        if len(a)==3:
            ans +=b
    
print(ans)

Submission status: Accepted

Solution code:
import sys
from itertools import combinations
N, *S = open(0).read().split()

T = [0]*5

for s in S:
    i = s[0]
    if i == 'M':
        T[0] += 1
    elif i == 'A':
        T[1] += 1
    elif i == 'R':
        T[2] += 1
    elif i == 'C':
        T[3] += 1
    elif i == 'H':
        T[4] += 1

T.sort(reverse=True)

k = 0
for t in T:
    if t:
        k += 1

ans = 0
for a, b, c in combinations(range(k), 3):
    ans += T[a] * T[b] * T[c]
print(ans)

Submission status: Accepted

Solution code:
N = int(input())
S = [0] * 5
for _ in range(N):
  s = input()
  if s[0] == "M": S[0] += 1
  elif s[0] == "A": S[1] += 1
  elif s[0] == "R": S[2] += 1
  elif s[0] == "C": S[3] += 1
  elif s[0] == "H": S[4] += 1

import itertools
ans = 0
for v in itertools.combinations(S, 3):
  ans +=  v[0] * v[1] * v[2]
print(ans)

Submission status: Accepted

Solution code:
from collections import defaultdict
n = int(input())
h = 'MARCH'
d = [0] * 5
for _ in range(n):
    s = input()
    if s[0] in h:
        d[h.find(s[0])] += 1

ans = 0
for i in range(5):
    for j in range(i, 5):
        if i == j:
            continue
        for k in range(j, 5):
            if i == k or j == k:
                continue
            ans += d[i] * d[j] * d[k]
print(ans)

Submission status: Accepted

Solution code:
from collections import defaultdict
from itertools import combinations
N = int(input())
cnt = defaultdict(int)

for _ in range(N):
    S = input()
    if S[0] in ["M","A","R","C","H"]:
        cnt[S[0]] += 1

if len(cnt) < 3:
    print(0)
    exit()

ans = 0
comb = list(combinations(["M","A","R","C","H"], 3))
for i in range(len(comb)):
    tmp = 1
    for c in comb[i]:
        tmp *= cnt[c]
    ans += tmp

print(ans)