Problem: Little Vasya loves orange juice very much. That's why any food and drink in his kitchen necessarily contains orange juice. There are n drinks in his fridge, the volume fraction of orange juice in the i-th drink equals pi percent.

One day Vasya decided to make himself an orange cocktail. He took equal proportions of each of the n drinks and mixed them. Then he wondered, how much orange juice the cocktail has.

Find the volume fraction of orange juice in the final drink.

Input

The first input line contains a single integer n (1 ≤ n ≤ 100) — the number of orange-containing drinks in Vasya's fridge. The second line contains n integers pi (0 ≤ pi ≤ 100) — the volume fraction of orange juice in the i-th drink, in percent. The numbers are separated by a space.

Output

Print the volume fraction in percent of orange juice in Vasya's cocktail. The answer will be considered correct if the absolute or relative error does not exceed 10  - 4.

Examples

Input

3
50 50 100


Output

66.666666666667


Input

4
0 25 50 75


Output

37.500000000000

Note

Note to the first sample: let's assume that Vasya takes x milliliters of each drink from the fridge. Then the volume of pure juice in the cocktail will equal <image> milliliters. The total cocktail's volume equals 3·x milliliters, so the volume fraction of the juice in the cocktail equals <image>, that is, 66.(6) percent.

Solution (in PYTHON3):

Solution:

'''l,lb=map(int,input().split())
ans=0
while l<=lb:
    l,lb=l*3,lb*2
    ans+=1
print(ans)
'''

'''q,t=map(int,input().split())
for i in range(t):
    if q%10==0:
        q=q//10
    else:
        q=q-1
print(q)'''

'''x=int(input())
if x<=5:
    print(1)
else:
    if x%5==0:
        print(x//5)
    else:
        print((x//5)+1)'''

'''s=input()
l=u=0
for i in s:
    if i.isupper():
        u+=1
    else:
        l+=1
if u>l:
    print(s.upper())
else:
    print(s.lower())'''


'''n,k=map(int,input().split())
lis1=[]
lis2=[]
if(k<=n//2):
    print((2**(k-1))+1)
else:
    print((2**((k//2)-1)))'''

#petya and strings
'''s1=input()
s2=input()
s1=s1.lower()
s2=s2.lower()
for i in range(len(s1)):
    if(s1[i]!=s2[i]):
        if(ord(s1[i])<ord(s2[i])):
            print("-1")
            break
        elif(ord(s1[i])>ord(s2[i])):
            print("1")
            break
else:
    print("0")'''

#young physicist

'''n=int(input())
s=0
for i in range(n):
    lis=[int(a) for a in input().split()]
    s=s+sum(lis)
    lis.clear()
if(s==0):
    print("YES")
else:
    print("NO")'''

#twins
'''n=int(input())
lis=[int(a) for a in input().split()]
lis.sort()
count=stol=0
while(True):
    stol=stol+lis.pop()
    rem=sum(lis)
    count+=1
    if(rem<stol):
        break
    
print(count)'''

#eshag loves big arrays
'''import collections
for i in range(int(input())):
    n=int(input())
    arr=[int(a) for a in input().split()]
    lis=collections.Counter(arr)
    mini=min(arr)
    for k,v in lis.items():
        if k==mini:
            print(len(arr)-v)
            break'''

'''for i in range(int(input())):
    n=int(input())
    arr=[int(a) for a in input().split()]
    maxi=max(arr)
    ans=0
    s=set()
    for i in range(len(arr)-1):
        count=0
        for j in range(i+1,len(arr)):
            if abs(arr[i]-arr[j])>=maxi:
                count+=1
        if(count==(len(arr)-(i+1))):
            ans+=1
    print(ans)'''
#presents
'''n=int(input())
lis=[int(a) for a in input().split()]
given=[0]*len(lis)
k=1
for i in lis:
    given[i-1]=given[i-1]+k
    k+=1
for i in given:
    print(i,end=" ")'''

#Magnets
'''n=int(input())
lis=[input() for j in range(n)]
flag=0
count=1
for i in range(len(lis)-1):
    if(lis[i]==lis[i+1]):
        continue
    else:
        count+=1  
print(count)'''

#In search of easy problem
'''n=int(input())
lis=[int(i) for i in input().split()]
if(lis.count(1)>=1):
    print("HARD")
else:
    print("EASY")'''

    
#kefa and first step
'''n=int(input())
lis=[int(j) for j in input().split()]
count=1
lis2=[]
if len(lis)==1:
    print(1)
else:
    for i in range(0,len(lis)-1):
        if(lis[i]<=lis[i+1]):
            count+=1
        else:
            lis2.append(count)
            count=1
        if(i==len(lis)-2):
            lis2.append(count)
    if(len(lis2)==1):
        print(lis2[0])
    else:
        print(max(lis2))'''

#hulk
'''n=int(input())
flag=0
for i in range(n):
    if(flag==0):
        print("I hate",end=" ")
        flag=1
    else:
        print("I love",end=" ")
        flag=0
    if(i==(n-1)):
        print("it")
    else:
        print("that",end=" ")'''
#i hate 1111
'''n=int(input())
for i in range(n):
    num=int(input())
    if(num%11==0):
        print("YES")
    else:
        while(len(str(num))>1):
            ex=len(str(num))*"1"
            if(num%int(ex)==0):
                print("YES")
                break
            num=num-int(ex)
        else:
            print("NO")'''
        
'''n=int(input())
lis=[int(a) for a in input().split()]
s=0
count=0
print(lis)
for i in lis:
    if(s+i>=0):
        s=s+i
        count+=1
print(count)'''

#caps lock
'''n=input()
start=n[0]
rem=n[1:]
if(len(n)==1):
    print(n.swapcase())
elif((start.islower() and rem.isupper()) or n.isupper()):
    print(n.swapcase())
else:
    print(n)'''

#stone game
'''for i in range(int(input())):
    n=int(input())
    lis=[int(a) for a in input().split()]
    ans=lis[::-1]
    mini=lis.index(min(lis))
    maxi=lis.index(max(lis))
    for i in range(len(lis)):
        if(lis[i]== mini or lis[i]==maxi):
            count+=1
            flag+=1
        else:
            count+=1
        if(flag==2):
            break
    for i in range((len(lis)-1),-1):
        if(lis[i]== mini or lis[i]==maxi):
            count1+=1
            flag1+=1
        else:
            count1+=1
        if(flag1==2):
            break
    for i in range((len(lis)//2))
    if ans.lfind(max(ans))>ans.rfind(max(ans)):
        mini=n-mini
    if n-maxi<maxi:
        maxi=n-maxi
    a=ans.index(min(lis))
    b=ans.index(max(lis))
    if mini+maxi==a+b:
        d=2+min(mini,a)+min(maxi,b)
        if mini+maxi<d and mini+maxi<a+b :
            print(1+mini+maxi)
        elif a+b<d and a+b<mini+maxi:
            print(a+b+1)
        else:
            print(d)
    else:
        if mini>a:
            mini=a
        if maxi>b:
            maxi=b
        print(1+mini+maxi)'''
'''import itertools
for i in range(int(input())):
    n,l,r=map(int,input().split())
    count=0
    lis=[int(a) for a in input().split()]
    com=list(itertools.combinations(lis,2))
    for i in com:
        i=list(i)
        s=sum(i)
        if(l<=s and s<=r):
            count+=1
    print(count)'''
#expression
'''lis=[]
lis2=[]
for i in range(3):
    lis.append(int(input()))
lis2.append((lis[0]+lis[1])*lis[2])
lis2.append((lis[0]*(lis[1]+lis[2])))
lis2.append((lis[0]*lis[1])*lis[2])
lis2.append((lis[0]+(lis[1]*lis[2])))
lis2.append((lis[0]*lis[1])+lis[2])
lis2.append((lis[0]+(lis[1]+lis[2])))
print(max(lis2))'''
#preety permutations
'''for t in range(int(input())):
    n=int(input())
    if(n==2):
        print("2 1")
    elif(n==3):
        print("3 1 2")
    else:
        if(n%2==0):
            for i in range(1,n+1,2):
                if(i!=(n-1)):
                    print(i+1,i,end=" ")
                else:
                    print(i+1,i)
        else:
            print("3 1 2",end=" ")
            for j in range(4,n+1,2):
                if(j!=(n-1)):
                    print(j+1,j,end=" ")
                else:
                    print(j+1,j)'''
#pleasant pairs
'''for i in range(int(input())):
    n=int(input())
    count=0
    lis=[int(a) for a in input().split()]
    for i in range(n-1):
        for j in range(i+1,n):
            if((i+1)+(j+1)==lis[i]*lis[j]):
                count+=1
    print(count)'''
#IQ test
'''n=int(input())
lis=[int(a) for a in input().split()]
counte=0
counto=0
for i in range(n):
    if(lis[i]%2==0):
        indexe=i+1
        counte+=1
    else:
        indexo=i+1
        counto+=1
if(counte==1):
    print(indexe)
else:
    print(indexo)'''
#gravity flip
'''n=int(input())
lis=[int(a) for a in input().split()]
lis.sort()
for i in lis:
    print(i,end=" ")'''
#ulter fast mathematician
'''str1=input()
str2=input()
for i in range(len(str1)):
    print(int(str1[i])^int(str2[i]),end="")'''
#drinks
n=int(input())
lis=[int(a) for a in input().split()]
s=sum(lis)
ans=s/(n*100)*100
print("%.12f"%ans)