Problem:
 Score : 200 points    Problem Statement Given is a sequence of N integers A_1, \ldots, A_N .  Find the (multiplicative) inverse of the sum of the inverses of these numbers, \frac{1}{\frac{1}{A_1} + \ldots + \frac{1}{A_N}} .      Constraints  1 \leq N \leq 100  1 \leq A_i \leq 1000         Input Input is given from Standard Input in the following format:  N  A_1  A_2  \ldots  A_N       Output Print a decimal number (or an integer) representing the value of \frac{1}{\frac{1}{A_1} + \ldots + \frac{1}{A_N}} .  Your output will be judged correct when its absolute or relative error from the judge's output is at most 10^{-5} .        Sample Input 1 2
10 30      Sample Output 1 7.5  \frac{1}{\frac{1}{10} + \frac{1}{30}} = \frac{1}{\frac{4}{30}} = \frac{30}{4} = 7.5 .  Printing 7.50001 , 7.49999 , and so on will also be accepted.       Sample Input 2 3
200 200 200      Sample Output 2 66.66666666666667  \frac{1}{\frac{1}{200} + \frac{1}{200} + \frac{1}{200}} = \frac{1}{\frac{3}{200}} = \frac{200}{3} = 66.6666... .  Printing 6.66666e+1 and so on will also be accepted.       Sample Input 3 1
1000      Sample Output 3 1000  \frac{1}{\frac{1}{1000}} = 1000 .  Printing +1000.0 and so on will also be accepted.

Solution (Python):
import sys

n=int( sys.stdin.readline().strip() )
a=[ int(x) for x in sys.stdin.readline().strip().split() ]

ans=0
for ai in a: ans+= ( 1.0 / ai )

print( "{:>.5e}".format(1.0/ans) )

Solution (Python):
N = int(input())
A = map(int,input().split())

abb = 0
for a in A:
  abb += 1/a

ans = 1/abb

print(ans)

Solution (Python):
n = int(input())
t_list = list(map(int,input().split()))
sum_ = 0
for one in t_list:
    sum_ += 1/one
print(1/sum_)

Solution (Python):
from sys import stdin

n = int(stdin.readline().rstrip())
an = list(map(int, input().split()))

sum = 0

for i in range(n):
  sum += 1/an[i]

ans = 1/sum

print(ans)

Solution (Python):
N = int(input())
As = list(map(int, input().split(" ")))

tmp_res = 0.0
for a in As:
    tmp_res += 1/a

res = 1/tmp_res

print(res)

Solution (Python):
N = int(input())
a = map(int,input().split())
ad = [1/i for i in a]
print(1/sum(ad))

Solution (Python):
N = int(input())
A = [int(i) for i in input().split()]

tmp = 0
for a in A:
    tmp += 1 / a

print(1 / tmp)

Solution (Python):
import sys
sys.setrecursionlimit(10**7)
def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x) - 1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def II(): return int(sys.stdin.readline())
def SI(): return sys.stdin.readline().strip()
INF = 10 ** 18
MOD = 10 ** 9 + 7

def main(): 
    N = II()
    a_li = LI()

    bunbo = 0
    for a in a_li:
        bunbo += (1/a)
    print(1/bunbo)


main()

Solution (Python):

N = int(input())
A = list(map(int, input().split()))
calc = 0

for i in A:
    calc += 1 / i

calc = 1 / calc

print(calc)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

s = 0
for ai in a:
    s += 1 / ai
print(1/s)

Solution (Python):
'''
allinputs = iter(input().splitlines())
input = lambda : next(allinputs)

N = int(input())
A = list(map(int, input().split()))

ans = 0

for i in range(N):
	ans += 1 / A[i]
	
ans = 1 / ans
print(ans)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))

under=0
for i in range(N):
    under+=1/A[i]
ans=1/under

print(ans)

Solution (Python):
n = int(input())
a = [1/int(i) for i in input().split()]

res = 1 / sum(a)
print(res)

Solution (Python):
N = int(input())
A = [int(a) for a in input().split()]

ans = 0
for a in A:
    ans += 1 / a
ans = 1 / ans
print(ans)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))
r = []
for a in A:
  r.append(1/a)
print(1/sum(r))

Solution (Python):
n = int(input())
a = list(map(lambda x: 1 / float(x), input().split()))

print(1 / sum(a))

Solution (Python):
n = int(input())
ans = 0.0
nn = [int(ni) for ni in input().split()]
for i in range(n):
    ans += (1/float(nn[i]))

print(1/ans)

Solution (Python):
def B():
    N = int(input())
    As = list(map(int, input().split()))

    print(1/sum([1/x for x in As]))


if __name__ == '__main__':
    B()

Solution (Python):
n = int(input())
nums = list(map(int,input().split()))
nums = [1/num for num in nums]
print(1/sum(nums))

Solution (Python):

from collections import Counter, defaultdict
import sys
sys.setrecursionlimit(10 ** 5 + 10)

from math import factorial
import heapq, bisect
import math
import itertools

def main():
    num = int(input())
    data = list(map(int, input().split()))

    bunbo = 0
    bunshi = 1
    for i in range(num):
        data[i] = 1 / data[i]
    ans = 1 / sum(data)

    
    print(ans)



if __name__ == '__main__':
    main()

Solution (Python):



N = int(input())
a = list(map(int, input().split()))
r = list(map(lambda x: 1.0 / float(x), a))
print(1.0 / sum(r))

Solution (Python):
n=int(input())
a=list(map(int, input().split()))
ans=0

for i in range(n):
    ans+=1/a[i]

print(1/ans)

Solution (Python):
a=int(input())
b=[int(i) for i in input().split()]
c=[]

for i in range(a):
  c.append(1/b[i])
  
print(1/sum(c))

Solution (Python):
n = int(input())

A = map(int, input().split())

ans = 0

for a in A:
    ans += 1.0 / a

print("%.10f" % (1.0 / ans))

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

tmp = 0
for i in A:
    tmp+=1/i
print(1/tmp)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
up = 0
for i in A:
  up += 1 / i
print('%.10f' % (1 / up))

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

molec = 1
for Ai in A:
    molec *= Ai

denom = 0
for Ai in A:
    denom += (molec // Ai)

print(molec / denom)

Solution (Python):
if __name__ == '__main__':
    n = int(input())
    a = list(map(float, input().split()))

    reverse_sum = 0
    for i in range(n):
        reverse_sum += 1/a[i]

    print(1/reverse_sum)

Solution (Python):
n = int(input())
a = list( map(int, input().split())) 

bunbo = 0
for i in range(n):
    bunbo += float(1/a[i]) 

print(1.0/bunbo)

Solution (Python):
c=int(input())
ne=list(map(int,input().split()))
ans=0
for i in range(c):
    ans=ans+1/ne[i]
print(1/ans)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))
s = 0
for i in a:
    s = s + (1/i)
print(1/s)

Solution (Python):
N=int(input())
A= list(map(int, input().split()))
s=0
for i in A:
    s+=1/i
print(1/s)

Solution (Python):
n = int(input())
l = list(map(int, input().split()))
res = 0
for i in range(n):
    res += 1 / l[i]
print(1/res)

Solution (Python):
def resolve():
    n=int(input())
    A=list(map(int,input().split()))
    ans=0
    for i in range(n):
        ans+=1/A[i]
    print(1/ans)
resolve()

Solution (Python):
n = int(input())
s = list(map(int,input().split()))
k = 0
for i in s:
    k+=(1/i)
print(1/k)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))
ans = 0
for i in range(N):
  ans += 1/A[i]
print(1/ans)

Solution (Python):
_ = input()
A = list(map(int,input().split()))

ansinv = 0

for a in A:
  ansinv += 1 / a

print(1 / ansinv)

Solution (Python):
N,*A=map(float,open(0).read().split())

c = 0 
for i in range(int(N)):
  c+=1/A[i]
c=1/c
print(c)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))

ans = 0

for i in range(n):
    ans +=(1/a[i])
    
print(1/ans)

Solution (Python):
N=int(input())
A = [int(i) for i in input().split()] 
wa=0

for i in range(N):
    wa=wa+1/A[i]
print(1/wa)

Solution (Python):
N = int(input())
A_list = list(map(int,input().split()))

result = 0
for i in range(N):
    result += 1/A_list[i]

print(1/result)

Solution (Python):
N = int(input())
S = list(map(int,input().split(' ')))

_ans = 0
for s in S:
  _ans += (1 / s)

print(1 / _ans)

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
ans=0
for i in range(n):
    ans+=1/a[i]
print(1/ans)

Solution (Python):
N = int(input())
A = [int(x) for x in input().split()]
print(1/sum(1/x for x in A))

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

summation = 0
for i in a:
    summation += 1 / i
print(1 / summation)

Solution (Python):
N = int(input())
A = [1/int(inp) for inp in input().split()]
print(1/sum(A))

Solution (Python):
import decimal,math
from collections import Counter,defaultdict
from fractions import gcd
from bisect import bisect_right,bisect_left
decimal.getcontext().prec = 10
N=int(raw_input())

arr=map(int,raw_input().split())
ans=1
for i in arr:
	ans=ans*i
ans1=0
for i in arr:
	ans1=ans1+(ans)/float(i)
print ans/float(ans1)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

s = 0
for i in range(n):
  s += 1/a[i]

print(1/s)

Solution (Python):
import sys
input=sys.stdin.readline

N = int(input())
A = list(map(int, input().split()))

x = 0
for i in A:
    x += 1/i
print(1/x)

Solution (Python):
inpl = lambda: list(map(int,input().split()))
N = int(input())
A = inpl()
print(1/sum(1/a for a in A))

Solution (Python):
N = input()
A = list(map(int, input().split()))

bumbo = sum([1/a for a in A])
print(1 / bumbo)

Solution (Python):
N = int(input())
a = list(map(int,input().split()))
sum = 0
for i in range(N):
    sum += 1/a[i]
print(1/sum)

Solution (Python):
n=int(input())
x=input().split()
ans=0
for i in range(n):
    ans+=1/int(x[i])
print(1/ans)

Solution (Python):
N = int(input())
A_list = list(map(int, input().split()))
sum = 0

for i in A_list:
  sum += 1/i
print(1/sum)

Solution (Python):
n=int(input())
a=list(map(int,input().split()))

bunbo=0

for i in range(n):
  bunbo+=1/a[i]

print(1/bunbo)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))
print(1/sum([1/i for i in a]))

Solution (Python):
def getlist():
	return list(map(int, input().split()))

N = int(input())
A = getlist()

s = 0
for i in range(N):
	s += 1 / A[i]

print(1 / s)

Solution (Python):
import sys
mod = 1000000007
def get_array(): return list(map(int, sys.stdin.readline().split()))
def get_ints(): return map(int, sys.stdin.readline().split())
def input(): return sys.stdin.readline()
def main():
    n = int(input())
    a = get_array()
    m = 1
    for e in a: m *= e
    s = 0
    for e in a: s  += m // e
    print(m/s)
if __name__ == "__main__":
    main()

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
for i in range(n):
  a[i] = 1 / a[i]
g=1/sum(a)
print(g)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
res = 1 / sum([1/a for a in A])
print(res)

Solution (Python):
n = int(input())
a = [int(i) for i in input().split()] 
bunbo = 0

for x in a:
  bunbo += 1/x
  
print(1/bunbo)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

ans = 0
for x in a:
    ans += 1/x

print(1/ans)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))

tmp_sum = 0
for i in range(N):
    tmp_sum += 1/A[i]

print(1/tmp_sum)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
x = 1/sum([1/i for i in a])
print(x)

Solution (Python):
N=int(input())
t=0
for i in input().split():
	i=int(i)
	t+=(1.0/i)
print(1.0/t)

Solution (Python):
N = int(input())
a_nums =[int(i) for i in input().split()]
ans = 0
for num in a_nums:
    ans +=1/num
print(1/ans)

Solution (Python):
'''
date +%Y.%m.%d

题解先咕着。
'''
def intinput():
    return [int(i) for i in input().split()]

n = intinput()
print(1 / sum([1 / i for i in intinput()]))

Solution (Python):
n = int(input())
li = list(map(int,input().split()))
gyaku = sum([1/_ for _ in li])
print(1/gyaku)

Solution (Python):
import sys

stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline().rstrip()  

n = ni()
a = na()

s = 0
for i in range(n):
    s += 1/a[i]
print("{:.14f}".format(1/s))

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
b = [1/i for i in a]
print(1/sum(b))

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
print(1 / sum([1 / Ai for Ai in A]))

Solution (Python):
N=int(input())
A=list(map(int,input().split()))



answer=0
for i in range(N):
  answer=answer +1/A[i]
  
print(1/answer)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
ans = 0
for i in range(N):
    ans += 1/A[i]
print(1/ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

ans = 0
for a in A:
    ans += 1.0/a
print(1/ans)

Solution (Python):
N =int(input())
A = list(map(int,input().split()))
B = 0

for i in range(N):
    B += 1/A[i]
print(1/B)

Solution (Python):
N = int(input())
As = list(map(int, input().split()))

print(1 / sum(1 / A for A in As))

Solution (Python):
n = int(input())
A = list(map(int, input().split()))

result = 0
for i in range(n):
    result += (1 / A[i])

print(1/result)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

ans = float(0)
for a in A:
    ans += 1/a
print(1/ans)

Solution (Python):
from sys import stdin
import math
import fractions
from collections import deque
from collections import Counter
import itertools

INF = 10 ** 10

N = int(stdin.readline().rstrip())
A = [int(x) for x in stdin.readline().rstrip().split()]

ans = 0

for Ai in A:
    ans += 1/Ai

ans = 1 / ans

print(ans)

Solution (Python):
n = int(input())
a = [1/int(x) for x in input().split()]
print(1/sum(a))

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

multiple = 1
for a in A:
    multiple *= a

denom = multiple
numer = 0
for a in A:
    numer += denom // a
    
print(denom / numer)

Solution (Python):
n = int(input())
A = list(map(int, input().split()))
result = 0
for a in A:
    result += 1/a



print(1/result)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
temp = 0

for i in range(n):
    temp += 1 / a[i]

print(1 / temp)

Solution (Python):
from fractions import Fraction
n = int(input())
a = list(map(int, input().split()))

d = 0
for i in range(n):
    d += Fraction(1, a[i])

print(float(Fraction(1, d)))

Solution (Python):
n = int(input())
s = list(map(int,input().split()))
k = 0
for i in s:
    k+=(1/i)
print(1/k)

Solution (Python):
N=int(input())
A=list(map(int, input().split()))
s=0
for i in range(N):
  s+=1/A[i]

print(1/s)

Solution (Python):
N = int(input())

a_list = list(map(int, input().split()))

all = 0
for a in a_list:
    b = 1 / a
    all += b

print(1/all)

Solution (Python):
def InputToInt():
    A = input().split()
    for i in range(len(A)):
        A[i] = int(A[i])
    return A


if __name__ == '__main__':
    N=int(input())
    A = InputToInt()
    su = 0
    for i in range(N):
        su += 1.0/A[i]
    print(1.0/su)

Solution (Python):
n=int(input())
a=list(map(float,input().split()))
for i in range(n):
  a[i]=1/a[i]
print(1/(sum(a)))

Solution (Python):
N = int(input())
A = list(map(int,input().split()))
tmp = 0
for a in A:
    tmp += 1 / a
print(1/tmp)

Solution (Python):
n = int(input())
ls = list(map(int,input().split()))
check = 0
for i in range(n):
    check += 1 / ls[i]
print(1 / check)

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
b=0
for i in range(n):
  b+=1/a[i]
print(1/b)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

bunbo = 0

for elm in a:
  bunbo += 1/elm

print(1/bunbo)

Solution (Python):
n = int(input())
def f(x):
    return 1 / int(x)
sum = sum(list(map(f, input().split())))

print(1/sum)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
sum = 0
for i in range(n):
  sum += (1/(a[i]))
print(1/sum)

Solution (Python):
N=int(input())
A=input().split()
for i in range(0,N):
    A[i]=int(A[i])
s=0
for i in range(0,N):
    s=s+(1/A[i])
print(1/s)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))

sum = 0
for i in a:
    sum+=1.0/i

print(1.0/sum)

Solution (Python):
import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,random,time,copy,functools
from collections import deque

sys.setrecursionlimit(10**7)
inf = 10**20
mod = 10**9 + 7

DR = [1, -1, 0, 0]
DC = [0, 0, 1, -1]

def LI(): return [int(x) for x in sys.stdin.readline().split()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
     
def main():
    N = I()
    A = LI()
    prod_sum = 0
    prod_a = 1
    for a in A:
        prod_a *= a
    for a in A:
        prod_sum += (prod_a/a)
    ans = prod_a/prod_sum
    print(ans)
main()

Solution (Python):
N=int(input())
A=list(map(int,input().split()))
ans = 0
for a in A:
    ans += 1 / a
print(1 / ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

hoge = 0
for i in range(N):
    hoge += 1/A[i]
print(1/hoge)

Solution (Python):
N = int(input())
A = [int(_) for _ in input().rstrip().split()]

sum = 0
for i in range(N):
    sum += 1/A[i]

print(1/sum)

Solution (Python):
N = int(input())
A = list(map(int, input().split(' ')))

sum = 0
for a in A:
    sum += 1 / a
print(1 / sum)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

c = 0
for i in a:
    c += 1 / i
print(1 / c)

Solution (Python):
N = int(input())
A = [int(i) for i in input().split()]
sum=0.
for i in A:
    sum+=1./i
print(1/sum)

Solution (Python):
''' بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ '''

gi = lambda : list(map(int,input().split()))
n, = gi()
l = gi()
print(1 / sum([1 / e for e in l]))

Solution (Python):
from scipy import stats

N = int(input())
A = list(map(int, input().split()))
print(stats.hmean(A) / N)

Solution (Python):
n = int(input())
a = [int(item) for item in input().split()]

base = 0
for item in a:
    base += 1.0 / item

print(1.0 / base)

Solution (Python):
N=int(input())
ans=0
l=list(map(int,input().split()))
for i in range(N):
  a=l[i]
  ans+=1/a
  
print(1/ans)

Solution (Python):
N = int(input())
A = map(float, input().split())

s = 1 / sum(map(lambda x: 1 / x, A))

print(s)

Solution (Python):
N=int(input())
A=list(map(int,input().split()))
B=0
for i in A:
    B+=(1/i)
print(1/B)

Solution (Python):
a=int(input())
s=list(map(int,input().split()))

goukei=0

for item in s:
  goukei+=1/item
  
  
  
print(1/goukei)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
child = 1 
mother = 0
for i in a:
  child *= i
for i in a:
  mother += child / i
print(child / mother)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))

s = 0
for a in A:
    s += 1/a

print(1/s)

Solution (Python):
n = int(input())
lst = list(map(int,input().split()))
ans = 0
for i in lst:
    ans += 1/i
print(1/ans)

Solution (Python):
n = int(input())
A = [int(x) for x in input().split()]

A = [1/x for x in A]

s = sum(A)
print(1/s)

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
bunbo=0
for i in a:
  bunbo+=1/i
ans=1/bunbo
print(ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
sum = 0
for a in A:
    sum += 1/float(a)
print(1/sum)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

B = 1 / sum(map(lambda x: 1/x, A))
print (B)

Solution (Python):
N = int(input())
A = list(map(int,input().split(" ")))

s = 0
for a in A:
    s += 1/a

print(1/s)

Solution (Python):
def main():
    N = int(input())
    A = list(map(int, input().split()))

    sumA = 0
    for a in A:
        sumA += 1 / a

    print( 1 / sumA ) 


main()

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
ans = 0
for a in A:
    ans += 1/a
print(1/ans)

Solution (Python):
n=int(input())
a=list(map(int,input().split()))

b=0
for i in a:
    b+=(1/i)
print(1/b)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))

s = 0
for i in range(n) :
    s += 1/a[i]

print(1/s)

Solution (Python):
import sys
def input(): return sys.stdin.readline().strip()

i  = lambda: int(input())
li = lambda: list(map(int, input().split()))

N = i()
A = li()

count = 0
for a in A:
  count += 1 / a

print(1 / count)

Solution (Python):
n = int(input())
s = input().split()
p=0
for i in s:
    p+=1/int(i)
print(1/p)

Solution (Python):
import numpy as np
N = int(input())
A_arr = np.array(list(map(int, input().split())))

print(1/np.sum(1/A_arr))

Solution (Python):
n = int(input())
a = list(map(int, input().strip().split()))

s = 0
for i in range(n):
    s += 1/a[i]

print(1/s)

Solution (Python):
n=int(input())
al=list(map(int,input().split()))
ar=[1/i for i in al]
print(1/sum(ar))

Solution (Python):
n = int(input())
a = list(map(int,input().split()))
bottom = 0
for i in a:
    bottom += 1/i
print(1/bottom)

Solution (Python):
import sys,collections as cl,bisect as bs
sys.setrecursionlimit(100000)
mod = 10**9+7
Max = sys.maxsize
def l(): 
    return list(map(int,input().split()))
def m(): 
    return map(int,input().split())
def onem(): 
    return int(input())
def s(x): 
    a = []
    aa = x[0]
    su = 1
    for i in range(len(x)-1):
        if aa != x[i+1]:
            a.append([aa,su])
            aa = x[i+1]
            su = 1
        else:
            su += 1
    a.append([aa,su])
    return a
def jo(x): 
    return " ".join(map(str,x))
def max2(x): 
    return max(map(max,x))
import fractions
from functools import reduce
def gcd(*numbers):
    return reduce(fractions.gcd, numbers)

def gcd_list(numbers):
    return reduce(fractions.gcd, numbers)
def lcm_base(x, y):
    return (x * y) // fractions.gcd(x, y)

def lcm(*numbers):
    return reduce(lcm_base, numbers, 1)

def lcm_list(numbers):
    return reduce(lcm_base, numbers, 1)


n = onem()

a = l()

su = 1
s = 0
for i in range(n):
    su *= a[i]

for i in range(n):
    s += su/a[i]

print(su/s)

Solution (Python):
import numpy as np

n = int(input())
aL = np.array(list(map(int,input().split())))
aL = 1/aL
print(1/np.sum(aL))

Solution (Python):
import numpy as np
import math
import sys
sys.setrecursionlimit(10000000)

def main():
    N = int(input())
    A = [int(c) for c in input().split()]
    num = 0
    for i in range(N):
        num += 1 / A[i]
    print(1/num)


if __name__ == '__main__':
    main()

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
s = 0
for ai in a:
    a_inv = 1 / ai
    s += a_inv
print(1 / s)

Solution (Python):
n=int(input())
ans=0
for i in map(int,input().split()):
    ans+=1/i

print(1/ans)

Solution (Python):
n = int(input())
a = [int(i) for i in input().split()]

result = 0
for j in a:
    result += 1/j
print(1/result)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
print(1/sum([1/i for i in a]))

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
x = 0
for i in range(N):
    x += 1/A[i]
print(1/x)

Solution (Python):
N = int(input())
a = list(map(int,input().split()))
k = 0
for i in range(N):
  k += 1/a[i]
print(1/k)

Solution (Python):
def p_b():
    N = int(input())
    A = list(map(int, input().split()))

    a = 0
    for i in A:
        a += 1 / i

    print(1 / a)


if __name__ == '__main__':
    p_b()

Solution (Python):
n = int(input().split()[0])
a_list = list(map(int, input().split()))

ans = 1 / sum([1/x for x in a_list])
print(ans)

Solution (Python):
N = int(input())
A = [1/int(i) for i in input().split()]

print(1/sum(A))

Solution (Python):
N=int(input())
A=list(map(int,input().split()))
B=[]
for i in range(len(A)):
    B.append(1/A[i])
print(1/sum(B))

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

ans = sum(1/a for a in A)
ans **= -1

print(ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

ans = 0
for i in A:
    ans += 1 / i

print(1/ans)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

print(1 / sum(map(lambda x: 1.0 / x, a)))

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

s = 0
for a in A:
    s += 1/a
print(1/s)

Solution (Python):
input()
array = [int(x) for x in input().split()]

inv_list = [1/num for num in array]

print(1 / sum(inv_list))

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

p = 1
for v in a:
    p *= v

b = 0
for v in a:
    b += p / v
print(p/b)

Solution (Python):
import numpy as np
n=int(input())
a=np.sum(1/np.array([int(i) for i in input().split(" ")]))
print(1/a)

Solution (Python):
n = int(input())
a = [int(i) for i in input().split()]

tmp = 0

for i in range(n):
    tmp += 1 / a[i]
    
print(1/tmp)

Solution (Python):
n = int(input())
A = list(map(int,input().split()))
L = []
for i in range(n):
  ra = 1/A[i]
  L.append(ra)
print(1/sum(L))

Solution (Python):
def resolve():
    n = int(input())
    a = list(map(int, input().split()))
    ans = 1 / sum([1 / ai for ai in a])
    print(ans)


if __name__ == "__main__":
    resolve()

Solution (Python):
n = int(input())
an = list(map(int, input().split()))

sum = 0
for a in an:
  sum += 1 / a
print(1 / sum)

Solution (Python):
n=int(input())
a=list(map(int, input().split()))

sum=0
for i in a:
    sum+=(1/i)
print(1/sum)

Solution (Python):
from fractions import Fraction

N = int(input())
sum = 0
for a in map(int, input().strip().split()):
	sum += Fraction(1, a)

print(float(1 / sum))

Solution (Python):
n=int(input())
a=list(map(int,input().split()))
wa=0
for i in range(n):
  wa+=1/a[i]
print(1/wa)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))
su = 0
for i in A:
    re = 1 / i
    su += re
print(1 / su)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))

ans = 0.0
for i in a:
  ans += 1/i

print(1/ans)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))
su = 0
for i in range(n):
  su += 1/a[i]
print(1/su)

Solution (Python):
N = int(input())

A = list(map(int, input().split()))

bunbo = 0.0
for i in range(N):
    bunbo += 1/A[i]

print(1/bunbo)

Solution (Python):
def main():
    _ = int(input())
    a = map(int, input().split())

    ans = 1 / sum([1 / aa for aa in a])
    print(ans)


main()

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
total = 0
for i in range(N):
    total += 1 / A[i]
print(1 / total)

Solution (Python):
n=int(input())
a=list(map(int, input().split()))
ans=0
for i in range(n):
    ans+=1/a[i]
print(1/ans)

Solution (Python):
N = int(input())
A = [int(i) for i in input().split()]

ans = 0
for i in range(N):
    ans += 1 / A[i]
print(1 / ans)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

bunbo = 0.0
for i in range(N):
    bunbo += 1/A[i]
ans = 1/bunbo
print(ans)

Solution (Python):
n = int(input())
a = [int(ii) for ii in input().split()]

sum = 0
for i in range(n):
    sum += 1.0/a[i]
print(1/sum)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))

k = 0

for i in range(n):
    k += 1/a[i]

print(1 / k)

Solution (Python):
n = int(input())
s = list(map(float, input().split()))
ans = 0.
for a in s:
  ans += 1./a
print(1./ans)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
ans = 0
for i in a:
  ans += 1/i
print(1/ans)

Solution (Python):
N = int(input())
A = [int(a) for a in input().split()]

sum = 0
for a in A:
    sum += 1/a
print(1/sum)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))

bunbo = 0 

for i in range(n):
    bunbo += 1/a[i]

print(1/bunbo)

Solution (Python):


import sys

def input(): return sys.stdin.readline().strip()
def list2d(a, b, c): return [[c] * b for i in range(a)]
def list3d(a, b, c, d): return [[[d] * c for j in range(b)] for i in range(a)]
def ceil(x, y=1): return int(-(-x // y))
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def Yes(): print('Yes')
def No(): print('No')
def YES(): print('YES')
def NO(): print('NO')
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
MOD = 10 ** 9 + 7

N = INT()
A = LIST()

sm = 0
for i in range(N):
    sm += 1 / A[i]
print(1/sm)

Solution (Python):
n = int( input() )
a = list( map( int, input().split() ) )

ans = 0
for num in a:
    ans += 1/num
ans = 1/ans

print(ans)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))


su = 0
p = 1
for i in a:
	p *= i

for i in a:
	su += (p/i)

print(p/su)

Solution (Python):
n = int(input())

A = list(map(int,input().split()))

ans = 0

for a in A:
  ans += 1 / a

print(1/ans)

Solution (Python):
n = int(input())
A = [1/int(el) for el in input().split(' ')]
B = sum(A)
print(1/B)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))
su = 1
for i in range(n):
    su = su* a[i]
b = []
for i in range(n):
    b.append(su/a[i])

hoge = 0
for i in range(n):
    hoge += b[i]

print(su/hoge)

Solution (Python):
n = int(input())
a = list(map(int,  input().split()))
sum = 0
for i in a:
    sum += 1/i

print(1/sum)

Solution (Python):
N=int(input())
A=list(map(int, input().split()))

temp=1/sum([1/A[i] for i in range(N)])

print(temp)

Solution (Python):
N = int(input())
As = [float(s) for s in input().split()]

t = 1
for a in As:
    t *= a

print(t / sum([t / a for a in As]))

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

mother = 0
for i in a:
	mother += 1/i
print(1/mother)

Solution (Python):
n=int(input())
lis=list(map(int,input().split()))
a=0
for i in range(n):
    a+=(1/lis[i])
print(1/a)

Solution (Python):
L=lambda:list(map(int,input().split()))
n=int(input())
a=L()
b=0
for i in a:b+=1/i
print(1/b)

Solution (Python):
n = int(input())
a = list(map(int, input().split()))

sans = 0
for i in range(n):
    sans += 1/a[i]

ans = 1/sans

print(ans)

Solution (Python):
n=int(input())
a=list(map(int,input().split(" ")))
bunbo=sum([1/i for i in a])
print(1/bunbo)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))

ans = 0
for i in range(N):
    ans += 1 / A[i]
print(1 / ans)

Solution (Python):


N = int(input())
A = list(map(int, input().split()))

sum_a = 0
for i in range(N):
    sum_a += 1.0 / A[i]

ans = 1.0 / sum_a

print(ans)

Solution (Python):
words = lambda t : list(map(t, input().split()))
n = int(input())
a = words(int)

print(1 / sum(map(lambda x: 1/x, a)))

Solution (Python):
n = int(input())
a = list(map(int, input().split()))
print(1 / sum(1 / i for i in a))

Solution (Python):
n = int(input())

a = list(map(int,input().split()))

a = list(map(lambda x: 1/x,a))

ans = 1/sum(a)

print(ans)

Solution (Python):
N = int(input())
As = [int(s) for s in input().split()]

ans = 0
for a in As:
  ans += float(1/a)
  
print(float(1)/ans)

Solution (Python):
n = int(input())
s = list(map(int,input().split()))
k = 0
for i in s:
    k+=(1/i)
print(1/k)

Solution (Python):
n = int(input())
a = [int(x) for x in input().split()]
ans = 0
for i in range(n):
    ans += 1/a[i]
ans = 1/ans
print(ans)

Solution (Python):
n = int(input())
A = list(map(int, input().split()))
sum = 0

for i in range(n):
    sum += (1/A[i])

print(1/sum)

Solution (Python):
n = int(input())
a = list(map(int,input().split())) 

ans = 0.0
for x in a:
  ans += 1/x

print(1/ans)

Solution (Python):
n = int(input())

A = list(map(int, input().split()))

ans = 0
for a in A:
    ans += 1 / a

print(1/ans)

Solution (Python):
n = int(input())
a = list(map(int,input().split()))
b = 0
for i in range(n):
  b += 1 / a[i]
print(1 / b)

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
sum = 0
for a in A:
    sum += 1/a
print(1/sum)

Solution (Python):
n = int(input())
a = [int(i) for i in input().split()]

A = 0
for i in range(n):
    A += 1 / a[i]
print(1/A)

Solution (Python):
N = int(input())
A = list(map(int,input().split()))
B = []
for i in range(N):
    B.append(1/A[i])
ans = 1/sum(B)
print(str(ans))