Buggy python submission (verdict: Runtime Error):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


from collections import defaultdict
def factor(n, m=None):
    # mを与えると、高々その素因数まで見て、残りは分解せずにそのまま出力する
    arr = defaultdict(int)
    temp = n
#     M = int(-(-n**0.5//1))+1
#     if m is not None:
#         M = min(m+1, M)
    M = 6
    for i in range(2, M):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr[i] = cnt

    return arr

n = int(input())
a = [None]*n
m = [[0]*19 for _ in range(19)]
ab = [None]*n
for i in range(n):
    s = input()
    if "." in s:
        ind = s.index(".")
        vv = len(s) - s.index(".") - 1
        v = int(s[:ind])*10**(vv) + int(s[(ind+1):])
        v *= 10**(9-vv)
    else:
        v = int(s)*10**9
    d = factor(v, 5)
    d.setdefault(2,0)
    d.setdefault(5,0)
    a,b = max(0, 18-d[2]), max(0, 18-d[5])
    m[a][b] += 1
    ab[i] = (d[2],d[5])
def cumsum2(v):
    # v: h*wの2次元リスト
    h,w = len(v), len(v[0])
    v.insert(0, [0]*w)
    for l in v:
        l.insert(0, 0)
    for i in range(1,h+1):
        for j in range(1,w+1):
            v[i][j] = v[i-1][j] + v[i][j-1] - v[i-1][j-1] + v[i][j]
    return v
m = cumsum2(m)
ans = 0
for a,b in ab:
    # print(a,b)
    ans += m[a+1][b+1]
    if a>=9 and b>=9:
        ans -= 1
print(ans//2)

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


from collections import defaultdict
def factor(n, m=None):
    # mを与えると、高々その素因数まで見て、残りは分解せずにそのまま出力する
    arr = defaultdict(int)
    temp = n
#     M = int(-(-n**0.5//1))+1
#     if m is not None:
#         M = min(m+1, M)
    M = 6
    for i in range(2, M):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr[i] = cnt

    return arr

n = int(input())
a = [None]*n
m = [[0]*19 for _ in range(19)]
ab = [None]*n
for i in range(n):
    s = input()
    if "." in s:
        ind = s.index(".")
        vv = len(s) - s.index(".") - 1
        v = int(s[:ind])*10**(vv) + int(s[(ind+1):])
        v *= 10**(9-vv)
    else:
        v = int(s)*10**9
    d = factor(v, 5)
    d.setdefault(2,0)
    d.setdefault(5,0)
    a,b = max(0, 18-d[2]), max(0, 18-d[5])
    m[a][b] += 1
    ab[i] = (d[2],d[5])
def cumsum2(v):
    # v: h*wの2次元リスト
    h,w = len(v), len(v[0])
    v.insert(0, [0]*w)
    for l in v:
        l.insert(0, 0)
    for i in range(1,h+1):
        for j in range(1,w+1):
            v[i][j] = v[i-1][j] + v[i][j-1] - v[i-1][j-1] + v[i][j]
    return v
m = cumsum2(m)
ans = 0
for a,b in ab:
#     print(a,b)
    ans += m[min(19,a+1)][min(19,b+1)]
    if a>=9 and b>=9:
        ans -= 1
print(ans//2)

Buggy python submission (verdict: Runtime Error):
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


from collections import defaultdict
def factor(n, m=None):
    # mを与えると、高々その素因数まで見て、残りは分解せずにそのまま出力する
    arr = defaultdict(int)
    temp = n
    M = int(-(-n**0.5//1))+1
    if m is not None:
        M = min(m+1, M)
    for i in range(2, M):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr[i] = cnt

    if temp!=1:
        arr[temp] = 1

    if not arr:
        arr[n] = 1

    return arr

n = int(input())
a = [None]*n
m = [[0]*19 for _ in range(19)]
ab = [None]*n
for i in range(n):
    s = input()
    if "." in s:
        ind = s.index(".")
        vv = len(s) - s.index(".") - 1
        v = int(s[:ind])*10**(vv) + int(s[(ind+1):])
        v *= 10**(9-vv)
    else:
        v = int(s)*10**9
    d = factor(v, 5)
    a,b = max(0, 18-d[2]), max(0, 18-d[5])
    m[a][b] += 1
    ab[i] = (d[2],d[5])
def cumsum2(v):
    # v: h*wの2次元リスト
    h,w = len(v), len(v[0])
    v.insert(0, [0]*w)
    for l in v:
        l.insert(0, 0)
    for i in range(1,h+1):
        for j in range(1,w+1):
            v[i][j] = v[i-1][j] + v[i][j-1] - v[i-1][j-1] + v[i][j]
    return v
m = cumsum2(m)
ans = 0
for a,b in ab:
    ans += m[a+1][b+1]
    if a>=9 and b>=9:
        ans -= 1
print(ans//2)

Fixed submission:
import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


from collections import defaultdict
def factor(n, m=None):
    # mを与えると、高々その素因数まで見て、残りは分解せずにそのまま出力する
    arr = defaultdict(int)
    temp = n
#     M = int(-(-n**0.5//1))+1
#     if m is not None:
#         M = min(m+1, M)
    M = 6
    for i in range(2, M):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr[i] = cnt

    return arr

n = int(input())
a = [None]*n
m = [[0]*19 for _ in range(19)]
ab = [None]*n
for i in range(n):
    s = input()
    if "." in s:
        ind = s.index(".")
        vv = len(s) - s.index(".") - 1
        v = int(s[:ind])*10**(vv) + int(s[(ind+1):])
        v *= 10**(9-vv)
    else:
        v = int(s)*10**9
    d = factor(v, 5)
    d.setdefault(2,0)
    d.setdefault(5,0)
    a,b = max(0, 18-d[2]), max(0, 18-d[5])
    m[a][b] += 1
    ab[i] = (d[2],d[5])
def cumsum2(v):
    # v: h*wの2次元リスト
    h,w = len(v), len(v[0])
    v.insert(0, [0]*w)
    for l in v:
        l.insert(0, 0)
    for i in range(1,h+1):
        for j in range(1,w+1):
            v[i][j] = v[i-1][j] + v[i][j-1] - v[i-1][j-1] + v[i][j]
    return v
m = cumsum2(m)
ans = 0
for a,b in ab:
#     print(a,b)
    ans += m[min(19,a+1)][min(19,b+1)]
    if a>=9 and b>=9:
        ans -= 1
print(ans//2)