Buggy python submission (verdict: Runtime Error):
#n = int(input())
#L = list(map(int, input().split()))
import math
import sys
import heapq
import fractions


def cmb(n, r):
    if n - r < r:
        r = n - r
    if r == 0:
        return 1
    if r == 1:
        return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2, r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1, r, p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N = int(input())
s = []
n = 0
for i in range(N):
    s.append(list(input()))
ans = 0


for i in range(N):
    s[i]=set(s[i])
    s[i].sort()
s.sort()

for i in range(1,N):

    if s[i]==s[i-1]:
        n += 1
        if i == N-1:
            ans += cmb(n+1, 2)
    else:
        if n > 0:
            ans += cmb(n+1,2)
            n = 0
print(ans)


Fixed submission:
#n = int(input())
#L = list(map(int, input().split()))
import math
import sys
import heapq
import fractions


def cmb(n, r):
    if n - r < r:
        r = n - r
    if r == 0:
        return 1
    if r == 1:
        return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2, r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1, r, p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N = int(input())
s = []
n = 0
for i in range(N):
    s.append(list(input()))
ans = 0


for i in range(N):
    s[i].sort()
s.sort()

for i in range(1,N):

    if s[i]==s[i-1]:
        n += 1
        if i == N-1:
            ans += cmb(n+1, 2)
    else:
        if n > 0:
            ans += cmb(n+1,2)
            n = 0
print(ans)

Buggy python submission (verdict: Runtime Error):
#n = int(input())
#L = list(map(int, input().split()))
import math
import sys
import heapq
import fractions

nCr = {}
def cmb(n, r):
    if r == 0 or r == n:
        return 1
    if r == 1:
        return n
    if (n, r) in nCr:
        return nCr[(n, r)]
    nCr[(n, r)] = cmb(n-1, r) + cmb(n-1, r-1)
    return nCr[(n, r)]

N = int(input())
s = []
n = 0
for i in range(N):
    s.append(list(input()))
ans = 0
s.sort()
for i in range(N):
    s[i]=set(s[i])
for i in range(N-1):
    if s[i]==s[i+1]:
        n += 1
        if i == N-2:
            ans += cmb(n+1, 2)
    else:
        if n > 0:
            ans += cmb(n+1,2)
            n = 0
print(ans)


Fixed submission:
#n = int(input())
#L = list(map(int, input().split()))
import math
import sys
import heapq
import fractions


def cmb(n, r):
    if n - r < r:
        r = n - r
    if r == 0:
        return 1
    if r == 1:
        return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2, r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1, r, p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N = int(input())
s = []
n = 0
for i in range(N):
    s.append(list(input()))
ans = 0


for i in range(N):
    s[i].sort()
s.sort()

for i in range(1,N):

    if s[i]==s[i-1]:
        n += 1
        if i == N-1:
            ans += cmb(n+1, 2)
    else:
        if n > 0:
            ans += cmb(n+1,2)
            n = 0
print(ans)

Buggy python submission (verdict: Runtime Error):
#n = int(input())
#L = list(map(int, input().split()))
import math
import sys
import heapq
import fractions

nCr = {}
def cmb(n, r):
    if r == 0 or r == n:
        return 1
    if r == 1:
        return n
    if (n, r) in nCr:
        return nCr[(n, r)]
    nCr[(n, r)] = cmb(n-1, r) + cmb(n-1, r-1)
    return nCr[(n, r)]

N = int(input())
s = []
n = 0
for i in range(N):
    s.append(list(input()))
ans = 0
s.sort()
for i in range(N):
    s[i]=set(s[i])
for i in range(N-1):
    if s[i]==s[i+1]:
        n += 1
        if i == N-2:
            ans += cmb(n+1, 2)
    else:
        if n > 0:
            ans += cmb(n+1,2)
        n = 0
print(ans)


Fixed submission:
#n = int(input())
#L = list(map(int, input().split()))
import math
import sys
import heapq
import fractions


def cmb(n, r):
    if n - r < r:
        r = n - r
    if r == 0:
        return 1
    if r == 1:
        return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2, r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1, r, p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N = int(input())
s = []
n = 0
for i in range(N):
    s.append(list(input()))
ans = 0


for i in range(N):
    s[i].sort()
s.sort()

for i in range(1,N):

    if s[i]==s[i-1]:
        n += 1
        if i == N-1:
            ans += cmb(n+1, 2)
    else:
        if n > 0:
            ans += cmb(n+1,2)
            n = 0
print(ans)

Buggy python submission (verdict: Runtime Error):

N = int(input())
S = []
for i in range(N):
    S.append(input())

kintama = 0
for i in range(len(S)):
    A = list(S[i])
    for j in range(i+1,len(S)+1):
        B = list(S[j])
        if set(A)==set(B):
            kintama += 1

print(kintama)



Fixed submission:
#n = int(input())
#L = list(map(int, input().split()))
import math
import sys
import heapq
import fractions


def cmb(n, r):
    if n - r < r:
        r = n - r
    if r == 0:
        return 1
    if r == 1:
        return n

    numerator = [n - r + k + 1 for k in range(r)]
    denominator = [k + 1 for k in range(r)]

    for p in range(2, r+1):
        pivot = denominator[p - 1]
        if pivot > 1:
            offset = (n - r) % p
            for k in range(p-1, r, p):
                numerator[k - offset] /= pivot
                denominator[k] /= pivot

    result = 1
    for k in range(r):
        if numerator[k] > 1:
            result *= int(numerator[k])

    return result

N = int(input())
s = []
n = 0
for i in range(N):
    s.append(list(input()))
ans = 0


for i in range(N):
    s[i].sort()
s.sort()

for i in range(1,N):

    if s[i]==s[i-1]:
        n += 1
        if i == N-1:
            ans += cmb(n+1, 2)
    else:
        if n > 0:
            ans += cmb(n+1,2)
            n = 0
print(ans)