Buggy python submission (verdict: Runtime Error):
MOD=10**9
from decimal import Decimal
import sys
input=sys.stdin.readline
    
def w(i,m):
    cnt=0
    while(i>0 and i%m==0):
        i//=m
        cnt+=1
    return cnt

N=int(input())
A=[int(Decimal(input())*Decimal(MOD)) for i in range(N)]
dic=[{} for i in range(N)]
dp=[[0]*51 for i in range(51)]

for i in range(N):
    dic[i][2],dic[i][5]=w(A[i],2),w(A[i],5)
    dp[dic[i][2]][dic[i][5]]+=1

for i in reversed(range(51)):
    for j in reversed(range(51)):
        if i==50 and j==50:
            continue
        if i==50:
            dp[i][j]+=dp[i][j+1]
        elif j==50:
            dp[i][j]+=dp[i+1][j]
        else:
            dp[i][j]+=dp[i][j+1]+dp[i+1][j]-dp[i+1][j+1]
ans=0

for i in range(N):
    t,f=max(18-dic[i][2],0),max(18-dic[i][5],0)
    res=dp[t][f]
    if t<=a and f<=b:
        res-=1
    ans+=res
print(ans//2)

Fixed submission:
from decimal import Decimal
import sys
input=sys.stdin.readline

    
def w(i,m):
    cnt=0
    while(i>0 and i%m==0):
        i//=m
        cnt+=1
    return cnt

N=int(input())
A=[int(Decimal(input())*Decimal(1000000000)) for i in range(N)]
dic=[None for i in range(N)]
dp=[[0]*51 for i in range(51)]

for i in range(N):
    d={}
    d[2],d[5]=w(A[i],2),w(A[i],5)
    dp[d[2]][d[5]]+=1
    dic[i]=d

for i in reversed(range(51)):
    for j in reversed(range(51)):
        if i==50 and j==50:
            continue
        if i==50:
            dp[i][j]+=dp[i][j+1]
        elif j==50:
            dp[i][j]+=dp[i+1][j]
        else:
            dp[i][j]+=dp[i][j+1]+dp[i+1][j]-dp[i+1][j+1]
ans=0

for i in range(N):
    d=dic[i]
    a,b=d[2],d[5]
    t,f=max(18-a,0),max(18-b,0)
    res=dp[t][f]
    if t<=a and f<=b:
        res-=1
    ans+=res
print(ans//2)

Buggy python submission (verdict: Time Limit Exceeded):
from decimal import Decimal
import sys
input=sys.stdin.readline

def factorization(n):
    arr={}
    tmp=n
    for i in range(2,int(n**0.5)+1):
        if(tmp%i==0):
            cnt=0
            while tmp%i==0:
                cnt+=1
                tmp//=i
            arr[i]=cnt
    if(tmp!=1):
        arr[tmp]=1
    return arr

N=int(input())
A=[int(Decimal(input())*Decimal(1000000000)) for i in range(N)]
dic=[None for i in range(N)]
dp=[[0]*51 for i in range(51)]

for i in range(N):
    d=factorization(A[i])
    dp[d.get(2,0)][d.get(5,0)]+=1
    dic[i]=d

for i in reversed(range(51)):
    for j in reversed(range(51)):
        if i==50 and j==50:
            continue
        if i==50:
            dp[i][j]+=dp[i][j+1]
        elif j==50:
            dp[i][j]+=dp[i+1][j]
        else:
            dp[i][j]+=dp[i][j+1]+dp[i+1][j]-dp[i+1][j+1]
ans=0

for i in range(N):
    d=dic[i]
    a,b=d.get(2,0),d.get(5,0)
    t,f=max(18-a,0),max(18-b,0)
    res=dp[t][f]
    if t<=a and f<=b:
        res-=1
    ans+=res
print(ans//2)

Fixed submission:
from decimal import Decimal
import sys
input=sys.stdin.readline

    
def w(i,m):
    cnt=0
    while(i>0 and i%m==0):
        i//=m
        cnt+=1
    return cnt

N=int(input())
A=[int(Decimal(input())*Decimal(1000000000)) for i in range(N)]
dic=[None for i in range(N)]
dp=[[0]*51 for i in range(51)]

for i in range(N):
    d={}
    d[2],d[5]=w(A[i],2),w(A[i],5)
    dp[d[2]][d[5]]+=1
    dic[i]=d

for i in reversed(range(51)):
    for j in reversed(range(51)):
        if i==50 and j==50:
            continue
        if i==50:
            dp[i][j]+=dp[i][j+1]
        elif j==50:
            dp[i][j]+=dp[i+1][j]
        else:
            dp[i][j]+=dp[i][j+1]+dp[i+1][j]-dp[i+1][j+1]
ans=0

for i in range(N):
    d=dic[i]
    a,b=d[2],d[5]
    t,f=max(18-a,0),max(18-b,0)
    res=dp[t][f]
    if t<=a and f<=b:
        res-=1
    ans+=res
print(ans//2)