peterverebics/CodeNet_Python_118 huggingface dataset:
import math
num1 = int(input())
num2 = math.floor(num1 / 1.08)
num3 = math.ceil(num1 / 1.08)
end = False
if math.floor(math.floor(num1 / 1.08) * 1.08) == num1:
  print(math.floor(num1 / 1.08))
  end = True
elif math.floor(math.ceil(num1 / 1.08) * 1.08) == num1 and end == False:
  print(math.ceil(num1 / 1.08))
else:
  print(':(')
import math
n = int(input())
a = math.ceil(n/1.08)
b = math.floor(a*1.08)
print(a*(n == b) or ":(")
N = int(input())

ans = -1
for i in range(1, N + 1):
	if int(i * 1.08) == N:
		ans = i

if ans != -1:
	print(ans)
else:
	print(":(")
n = int(input())
limax = 46298

for i in range(limax+1):
    if int(i*1.08) == n:
        print(i)
        break
    elif i == limax:
        print(':(')
    else:
        pass
N = int(input())
res = int(N / 1.08)
if int(res * 1.08) == N:
    print(res)
elif int((res + 1) * 1.08) == N:
    print(res + 1)
else:
    print(':(')
n = int(input())
for x in range(n+1):
    if x * 108 // 100 == n:
        print(x)
        break
else:
    print(':(')
n = int(input())

p2 = (n + 1) / 1.08
p1 = n / 1.08
if p2 > int(p2) >= p1:
    print(int(p2))
else:
    print(":(")
N = int(input())

for x in range(50001):
  y = int( x * 1.08 )
  if y == N:
    print(x)
    exit()
    
print(":(")
import math
N=int(input())
a=int(N//1.08)
b=int(N//1.08+1)
if math.floor(a*1.08)==N:
    print(a)
elif math.floor(b*1.08)==N:
    print(b)
else:
    print(":(")
N = int(input())
import math
if int(math.floor((math.ceil(N/1.08) * 1.08)))==N:
    print(int(math.ceil(N/1.08)))
else:
     print(":(")
N = int(input())

ans = 0
for i in range(1, N + 1):
    if int(i*1.08) == N:
        ans = i

if ans != 0:
    print(ans)
else:
    print(":(")
from math import ceil, floor


def main(n: int):
    ans = ceil(n / 1.08)

    if floor(ans * 1.08) == n:
        print(ans)
    else:
        print(':(')


if __name__ == "__main__":
    n = int(input())

    main(n)
n=int(input())
for i in range(1,n+1):
    if (i *108)//100 ==  n:
        print(i)
        exit()
print(':(')
n = int(input())

import math

def cal():
    for i in range(n+1):
        if n == int(i * 1.08):
            return i
    return 0

ans = cal()
if ans:
    print(ans)
else:
    print(':(')
n = int(input())

import math

def cal():
    for i in range(n+1):
        if n == math.floor(i * 1.08):
            return i
    return 0

ans = cal()
if ans:
    print(ans)
else:
    print(':(')
n = int(input())
for i in range(1, n + 1):
    ans = int(i * 1.08)
    if ans == n:
        print(i)
        quit()
print(':(')
import math

N=int(input())
M=N/1.08

s = str(math.floor(M)) if N == int(math.floor(M)*1.08) else  str(math.ceil(M)) if N == int(math.ceil(M)*1.08) else ':('

print(s)
def resolve():
    N = int(input())
    a = int(N // 1.08)
    if int(a * 1.08) == N:
        print(a)
    elif int((a + 1) * 1.08) == N:
        print(a + 1)
    else:
        print(":(")
resolve()
from math import floor
n = int(input())

for i in range(1, 50000 + 1):
    if floor(i * 1.08) == n:
        print(i)
        break
else:
    print(':(')
n = int(input())
if n%1.08==0:
  print(int(n//1.08))
else:
  x_init=n//1.08 + 1
  x_n = int(1.08*x_init)
  if x_n ==n:
    print(int(x_init))
  else:
    print(':(')
# B - Tax Rate
N = int(input())
ans = ':('
for x in range(50000):
    if (108*x)//100==N:
        ans = x
        break
print(ans)
import math
N = int(input())
A = N/1.08 
B = (N+1)/1.08 

if math.ceil(N/1.08) < math.ceil((N+1)/1.08 ):
  print(math.ceil(N/1.08))
else:
  print(':(')
from math import ceil
n=int(input())
""" flag=True
xceil=ceil(n/1.08)
xfloor=int(n/1.08)
for i in range(xfloor,xceil+1):
    if int(i*1.08)==n:
        print(i)
        flag=False
        break
if flag:
    print(":(") """

flag = True
for i in range(1,50001):
    if int(i*1.08)==n:
        print(i)
        flag=False
        break
if flag:
    print(":(")
import math
N = int(input())
flag = False
Min = math.floor(N / 1.08)
Max = math.floor( ( N + 1 ) / 1.08 + 1)
for i in range(Min, Max + 1):
  if math.floor( i * 1.08 ) == N:
    print( i )
    flag = True
    break
if not flag:
  print(':(')
n = int(input())

for i in range(50001):
    if int(i*1.08) == n:
        print(int(i))
        quit()
print(":(")
import math
n = int(input())
ans = math.ceil(n/1.08)
if math.floor((math.ceil(n/1.08))*1.08) != n:
    ans = ':('
print(ans)
import math

N = int(input())
ans = math.ceil(N // (1.08))


while math.floor(ans*1.08) < N:
  ans += 1
  if math.floor(ans*1.08) == N:
    print(ans)

  elif math.floor(ans*1.08) > N:
    print(':(')
n = int(input())
import math
a = n*100/108
b = (n*100+100)/108
ans = math.ceil(a) if math.ceil(a) < b else ":("
print(ans)
import math
i=int(input())
ans=math.ceil(i/1.08)
if math.floor(ans*1.08)==i:
    print (ans)
else:
    print (":(")
import math
n = int(input())
for i in range(1,50001):
    if math.floor(i * 1.08) == n:
        print(i)
        break
else:
    print(":(")
import math
N = int(input())
flag = True
for i in range(N):
  x = math.floor((i+1)*1.08)
  if (x == N):
    print(i+1)
    flag = False
    break
if (flag):
  print(':(')
n = int(input())

n_origin = int(n * 100 / 108.)
if int(n_origin * 108 / 100.) == n:
    print(n_origin)
elif int((n_origin + 1) * 108 / 100.) == n:
    print(n_origin + 1)
else:
    print(":(")
import math
N = int(input())

f = int(N // 1.1)

ok = False
while True:
  n = math.floor(f * 1.08)
  if n == N:
    ok = True
    break
  elif N < n:
    break
    
  f += 1
  
if not ok:
  print(':(')
else:
  print(f)
def resolve():
    import math as m
    N = int(input())
    nn = m.ceil(N / 1.08)
    if m.floor(nn * 1.08) == N:
        print(nn)
    else:
        print(":(")


resolve()
import math
N = int(input())

x = N //1.08
y = x + 1

if (math.floor(x * 1.08) == N):
    print(int(x))
elif(math.floor(y * 1.08) == N):
    print(int(y))
else:
    print(":(")
N = int(input())

n = int(N/1.08)
while int(n*1.08) <= N:
    if int(n*1.08) == N:
        print(n)
        break
    else:
        n += 1
else:
    print(":(")
N = int(input())
a = int(N / 1.08) # min
b = int((N + 1)  / 1.08) # max
ans = ':('
for i in range(a, b + 1):
    if int(i * 1.08) == N:
        ans = i
        break
print(ans)
n=int(input())

for i in range(50000):
 if int(i*1.08)== n:
  print(i)
  exit()
  
print(':(')
N=int(input())
for x in range(1,N+1):
  if int(1.08*x)==N:
    print(x)
    break
  if x==N:
    print(":(")
N=int(input())
A=int(N//1.08)
if N==int(A*1.08):
    print(A)
elif N==int((A+1)*1.08):
    print(A+1)
else:
    print(':(')
import math

n = int(input())
ans = ':('
a = n / 1.08

for i in range(math.floor(a - 2) , math.ceil(a + 2)):
  if math.floor(i * 1.08) == n:
    ans = i
    break

print(ans)
import math as m

n = int(input())
x = m.ceil(n/1.08)
if(m.floor(x*1.08) == n):
    print(x)
else:
    print(":(")
import sys
sys.setrecursionlimit(10 ** 5 + 10)
def input(): return sys.stdin.readline().strip()

def resolve():
    N=int(input())
    x = 1

    while True:
        if N<=x*1.08<N+1:
            print(x)
            break
        elif x>N:
            print(':(')
            break
        else:
            x+=1
            



resolve()
# -*- coding: utf-8 -*-
import math
def main():
    N = int(input())
    if N % 1.08 == 0:
        print(N/1.08)
    else:
        x = math.ceil(N/1.08)
        if x < (N+1)/1.08:
            print(x)
        else:
            print(':(')
    return
if __name__ == '__main__':
    main()
n = int(input())
x, mod = divmod(n, 1.08)
print(x if mod == 0 else
      int(x + 1) if int((x+1)*1.08) == n
      else ':(')
import math

N = int(input())
raw = math.ceil(N / 1.08)
check = raw * 1.08

if int(check) == N:
  print(raw)
else :
  print(":(")
n = int(input())
x = n * 100 // 108

if int(x * 1.08) == n:
    print(x)
elif int((x+1) * 1.08) == n:
    print(x+1)
else:
    print(':(')
N = int(input())

ans_cand = int(N/1.08)
if int(ans_cand*1.08) == N:
    print(ans_cand)
elif int((ans_cand+1)*1.08) == N:
    print(ans_cand+1)
else:
    print(':(')
# n, m, l = map(int, input().split())

# list_n = list(map(int, input().split()))

# n = input()
# list = [input() for i in range(N)

# list = [[i for i in range(N)] for _ in range(M)]

N = int(input())

Xf = N / 1.08

if int(Xf) == Xf:
    print(int(Xf))
elif int((int(Xf)+1)*1.08) == N:
    print(int(Xf)+1)
else:
    print(":(")
import math

N = int(input())

a = math.ceil(N/1.08)
if math.floor(a*1.08) == N:
    print(a)
else:
    print(':(')
import math
N = int(input())
flg = False

for i in range(N+1):
    if N == math.floor(i * 1.08):
        flg = True
        break
if flg:
    print(i)
else:
    print(":(")
import sys
def input(): return sys.stdin.readline().rstrip()
def main():
    n=int(input())
    for x in range(n//2,n+1):
        if x*1.08//1==n:
            print(x)
            break
    else:print(":(")

if __name__=='__main__':
    main()
import sys
n = int(input())
 
for i in range(n+1):
  if i*108//100 == n:
    print(i)
    sys.exit()
    
print(":(")
# Input the amount of money Takahashi paid
N = int(input())
 
# Check if the price before tax is X, for X = 1, 2, 3, ..., N
ans = -1
for i in range(1, N + 1):
	if int(i * 1.08) == N:
		ans = i
 
# Print answer
if ans != -1:
	print(ans)
else:
	print(":(")
def main():
    import sys
    def input(): return sys.stdin.readline().rstrip()
    n = int(input())
    for i in range(1,n+1):
        u = 108*i//100
        if u == n:
            print(i)
            break
        elif u > n:
            print(':(')
            break


if __name__ == '__main__':
    main()
import math
N=int(input())
if (N/1.08).is_integer()==True:
    S=int(N/1.08)
else:
    S=math.ceil(N/1.08)
if (S*1.08)//1==N:
    print(S)
else:
    print(':(')
def main():
    import math

    n = int(input())
    x, y = n / 1.08, (n + 1) / 1.08
    a, b = math.floor(x), math.ceil(y)

    for i in range(a, b):
        if math.floor(1.08 * i) == n:
            print(i)
            break
    else:
        print(':(')


if __name__ == '__main__':
    main()
import sys
input = sys.stdin.readline

import math

def main():
    n = int(input())

    x = int(math.ceil(n / 1.08))
    xn = int(x*1.08)

    # print('x',x)
    # print('xn',xn)

    if xn == n:
        print(x)
    else:
        print(':(')




if __name__ == '__main__':
    main()
import math

n=int(input())

num=math.ceil(n/1.08)

if math.floor(num*1.08)==n:
  print(num)
else:
  print(":(")
N = int(input())

resultA = N * 100 // 108
resultB = resultA + 1
valueA = resultA * 108 // 100
valueB = resultB * 108 // 100

if N == valueA:
  print(resultA)
elif N == valueB:
  print(resultB)
else:
  print(':(')
import math

n = int(input())
# x = int(n/1.08+.5)
x = math.ceil(n/1.08)
print(x) if math.floor(x*1.08) == n else print(':(')
import math
n = int(input())
mx = 50000

for i in range(mx):
    if math.floor(i*1.08) == n:
        print(i)
        exit()
else:
    print(":(")
N=int(input())
import math
if N%(1.08)==0:
    print(int(N/1.08))
else:
    a=N//1.08+1
    b=math.floor(a*1.08)
    if N==b:
        print(int(a))
    else:
        print(':(')
import math


def resolve():
    N = int(input())
    x = int(N // 1.08)
    if math.floor(x * 1.08) == N:
        print(x)
    elif math.floor((x + 1) * 1.08) == N:
        print(x + 1)
    else:
        print(":(")


if __name__ == "__main__":
    resolve()
N = int(input())
for X in range(N):
    if int(X * 1.08) == N:
        print(X)
        exit()
print(":(")
import math
n = int(input())
print(math.ceil(n/1.08)*(math.ceil(n/1.08) == math.floor(-~n/1.08)) or ":(")
n = int(input())
for i in range(1, n):
  if round(i * 1.08) == n:
    print(i)
    exit()
print(':(')
import math
N = int(input())
num1 = math.floor(N / 1.08)
num2 = math.ceil(N / 1.08)
num3 = math.floor(num1 * 1.08)
num4 = math.floor(num2 * 1.08)
if N == num3 or N == num4:
  print(N)
else:
  print(':(')
n = int(input())
x = round(n / 1.08)
d = int(x * 1.08)
if n == d:
    print(x)
else:
    print(":(")
import math
a = int(input())
for i in range(a):
    if math.floor(i*1.08) == a:
        print(i)
        exit()
print(":(")
import math

N = int(input())

mini = math.ceil(N / 1.08)
maxx = math.floor((N + 1) / 1.08)

if (mini <= maxx):
    ans = mini
else:
    ans = ':('

print(ans)
n = int(input())
import math
a = n*100/108
b = (n*100+100)/108
ans = math.ceil(a) if math.ceil(a) != b else ":("
print(ans)
import math
N = int(input())

if math.ceil(N / 1.08) * 1.08 == N:
  print(math.ceil(N / 1.08))
else:
  print(':(')
import math
n=int(input())
for i in range(n):
    if math.floor(i*1.08)==n:
        print(i)
        break
    elif math.floor(i*1.08)>n:
        print(":(")
        break
import math
N = int(input())

if math.ceil(N / 1.08) != N:
  print(':(')
else:
  print(math.ceil(N / 1.08))
import math
N = int(input())
X = math.floor(N/1.08)
if N == X*1.08:
 print(X)
else:
 print(':(')
N = int(input())

X = N / 1.08

behind_point = X - int(X)
cond = behind_point == 0.0 or behind_point >= 0.5
if behind_point == 0.0:
    ans = int(X)
elif behind_point >= 0.5:
    ans = int(X) + 1
else:
    ans = ':('
print(ans)
# N=1079
N=int(input())

ans=int(round((N*100/108)+0.01))

if (ans*1.08)//1 == N:
    print(ans)
else:
    print(":(")
import sys
input = sys.stdin.readline

def main():
    n = int(input())
    for x in range(1, n):
        if int(x * 1.08) == n:
            print(x)
            return
    
    print(":(")

main()
import math

N = int(input())
X = 0
a = 0
for i in range(N):
  X = math.floor(1.08*i)
  if(X==N):
    print(i)
    a+=1
    break
if(a ==0):
  print(":(")
n = int(input())
x = int(n/1.08+.5)
print(x) if int(x * 1.08) == n else print(':(')
import math
N = int(input())

ans =0

for i in range(N):
  if math.floor(i*1.08) == N:
    print(i)
    ans += 1
    
if ans == 0:
  print(':(')
import math
N = int(input())
count = 0
ans = 0
for i in range(N):
    money = 0
    money = math.floor(i*1.08)
    if money == N:
        count += 1
        ans = i
        break
if count == 0:
    print(":(")
else:
    print(ans)
def readinput():
    n=int(input())
    return n

def main(n):
    x7=int(n/1.07)
    x8=int(n/1.08)
    x9=int(n/1.09)
    n100=n*100
    for x in range(max(1,x9-1),x7+1):
        xx=x*108//100
        if xx==n:
            print(x)
            break
    else:
        print(':(')

        

if __name__=='__main__':
    n=readinput()
    main(n)
import sys
N=int(input())
a=N//1.08
c=a+1
d=a-1
b=a*1.08
b=int(b)
if b==N:
  print(a)
  sys.exit()
elif int(c*1.08)==N:
  print(c)
elif int(d*1.08)==N:
  print(d)
# N=1079
N=int(input())

a=N*100/108
b=(N+1)*100/108

if a+1 <b:
    print(int(round(a+0.5)))
else:
    print(":(")
import math

n = int(input())
for i in range(1,n):
    if math.floor(i * 1.08) == n:
        print(i)
        exit(0)
print(":(")
n = int(input())

for i in range(n):
	if int(i * 1.08) == n:
		print(int(i))
		exit()

print(":(")
from math import floor
n = int(input())
for i in range(1,n):
    if floor(i*1.08) == n:
        print(i)
        break
else:
    print(":(")
n=int(input())
m=round(n/float(1.08))
if int(m*float(1.08))==n:
  print(m)
else:
  print(':(')
n = int(input())
ans = int(n*100/108+0.5)
if int(ans*1.08)==n:
    print(ans)
else:
    print(":(")
n=int(input())
m=int(n/1.08)
if n!=int(m*1.08):
  print(":(")
else:
  print(m)
import math
n = int(input())
x1 = math.ceil(n/1.08)
x2 = math.floor((n+1)/1.08)
print(':(' if x2<x1 else x1)
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)

n = int(input())

def binary_search(ok, ng, cond):
    while abs(ok - ng) > 1:
        mid = (ok + ng) / 2
        if cond(mid):
            ok = mid
        else:
            ng = mid
    return ok

candidate = int(binary_search(n, 0, lambda x: x * 1.08 >= n))
if n == int(candidate * 1.08):
    print(candidate)
else:
    print(':(')
n = int(input())

for i in range(n):
    if int(i * 1.08) == n:
        print(i)
        exit()
print(":(")
# N=1079
N=int(input())

ans=int(round((N*100/108)+0.5))

if (ans*1.08)//1 == N:
    print(ans)
else:
    print(":(")
import math
N=int(input())
X=math.ceil(N/1.08)
if math.floor(X*1.08)==N:
    print(X)
else:
    print('：（')
N = int(input())
for x in range(1,10000):
  if x*108//100==N:
    print(x)
    break
if x==9999:
  print(":(")
import math
N=int(input())
x=math.ceil(N/1.08)
X=math.floor((N+1)/1.08)
if math.floor(x) < math.floor(X):
  print(x)
else:
  print(":(")
def resolve():
    N = int(input())
    if (N + 1) * 100 % 108 == 0:
        print(":(")
    else:
        print(int((N+1)/1.08))
resolve()
n = int(input())
a = int(n/1.08)
if int(a*1.08) == n:
  print(a)
elif int((a+1)*1.08) == n:
  print(a+1)
else:
  (':(')
n=int(input())
num=round(n/1.08)
check=int(num*1.08)
if check==n:
    print(num)
else:
    print(':(')
n = int(input())
for i in range(n):
    tmp=i*1.08//1
    if tmp==n:
        print(i)
        exit(0)
print(":(")
from math import floor
n = int(input())

for x in range(n):
    cost = floor(x * 1.08)
    if cost == n:
        print(x)
        exit()
print(":(")
N=int(input())

ans=round(N/1.08)
if int(ans*1.08)==N:
    print(ans)
else:
    print(":(")
# sumitb2019_b_bacha.py
N = int(input())
for i in range(N):
    if int(i*1.08) == N:
        print(i)
        exit()
print(":(")
n = int(input())
for i in range(n):
  if int(i * 1.08) == n:
    print(i)
    exit()
print(":(")
import math
N = int(input())
S = N / 1.08
if math.ceil(S) * 1.08 != N:
  print(":(")
else:
  print(math.ceil(S))
N = int(input())
for i in range(N):
  price = int(i * 1.08)
  if(price == N):
    print(i)
    exit()
print(":(")
#B
n=int(input())
ans=None
for i in range(1,46297):
    if int(i*1.08)==n:
        ans=i
        break
    if i==46296:
        ans=":("
print(ans)
# -*- coding: utf-8 -*-
import math

N = int(input())

for x in range(N,1,-1):
    val = int(x * 1.08)
    if val == N:
        print(x)
        exit()

print(':(')
import math
N = float(input())
x = round(N * 100 / 108)
if math.floor(x * 1.08) == N :
    print(x)
else :
    print(':(')
import math

N = int(input())
a = math.ceil(N/1.08)
b = math.floor((N+1)/1.08)
tmp = list(range(a,b+1))
print(tmp[0] if tmp else ':(')
N = int(input())

x = round(N/1.08)

if N == int(x*1.08):
    print(x)
else:
    print(":(")
N = int(input())
if (N*100)%108 == 0 :
    print(N/1.08)
else :
    for i in range(1,100) :
        if (N*100+i) % 108 == 0 :
            print((N*100+i)/108)
            break
    else :
        print(":(")
n = int(input())
a = n//1.08
print(int(a+1))
N = int(input())

for i in range(N-1):
    X = i * 1.08
    if int(X) == N:
        print(i)
        exit()

print(':(')
n = int(input())
stp = int(n/1.08)
while True:
  cost = int(stp*1.08)
  if cost == n:
    ans = cost
    break
  elif cost > n:
    ans = ':('
    break
  else:
    stp += 1
print(ans)
N = int(input())
for x in range(1,10000):
  if int(x*1.08)==N:
    print(x)
    break
if x==9999:
  print(":(")
import math

N = int(input())

def solve(n):
    for i in range(n):
        if math.floor(i * 1.08) == n:
            print(i)
            return
    print(':(')

solve(N)
import math
n = int(input())
found = False
for y in range(n):
    if n == math.floor(y*1.08):
        print(y)
        found = True
        break
if (found == False):
    print(":(")
n=int(input())
x=int(n/1.08)
if int(x*1.08)==n:
    print(x)
else:
    print(":(")
n=int(input())
for i in range(1,n):
    if int(i*1.08) == n:
        print(i)
        break
else:
    print(':(')
import math


# For taking integer inputs.
def inp():
    return(int(input()))


n = inp()
res = round(n/1.08)
if math.floor(res*1.08) >= n:
    print(res)
else:
    print(":(")
import math
f = True
N = int(input())
for i in range(N):
    if math.floor(i*1.08) == N:
        print(i)
        f = False
if f:
    print(":(")
N=int(input())

for i in range(N):
	if round(i*1.08)==N:
		print(i)
		exit()
print(":(")
import sys

stdin = sys.stdin

ns = lambda : stdin.readline().rstrip()
ni = lambda : int(ns())
na = lambda : list(map(int, stdin.readline().split()))
sys.setrecursionlimit(10 ** 7)

def main():
    n = ni()

    x = round(n / 1.08)
    y = x+1
    z = x -1
    # print(x * 1.08, y*1.08, z*1.08)
    # print(x, y, z)
    if x == n:
        print(x)
    elif y == n:
        print(y)
    elif z == n:
        print(z)
    else:
        print(":(")

if __name__ == '__main__':
  main()
n = int(input())

r = n % 27
if r == 13 or r == 26:
    print(':)')
elif r ==0:
    x = int(100*n/108)
    print(x)
else:
    for i in range(1, 25):
        if 1.08*(i-1) < r <= 1.08*i:
            break
    x = int(100*(n - i)/108) + i
    print(x)
N = int(input())

for i in range(N):
    if int(i * 1.08) == N:
        print(i)
        exit(0)
else:
    print(":(")
n = int(input())

dic = {}
for i in range(1,50000):
    dic[int(i * 1.08)] = i
print(dic)

if n in dic:
    print(dic[n])
else:
    print(':(')
import sys
n = int(input())

for i in range(n):
  if i*108//100 == n:
    print(i)
    sys.exit()
    
print(":(")
n = int(input())

for i in range(1, n):
    if round(i * 1.08) == n:
        print(i)
        exit()
print(':(')
N=int(input())

if ((N//1.08)+1)*1.08==N:
  print((N//1.08)+1)
if (N//1.08)*1.08==N:
  print(N//1.08)
else:
  print(":(")
x = int(input())

b = x//1.08
x1 = int(b*1.08)
x2 = int((b+1)*1.08)

if x1 == x:
  print(b)
elif x2 == x:
  print(b+1)
else:
  print(":(")
import sys
input=sys.stdin.buffer.readline
N=int(input())
tax=27/25
for i in range(1,N):
    money=int(i*tax)
    if money==N:
        print(money)
        exit(0)
print(":(")
N = int(input())
X = round(N / 1.08)

#再計算
if (X * 1.08) // 1 == N:
    print(X)
else:
    print(":(")
n = int(input())

for i in range(n + 1) :
	if int(i * 1.08) == n:
		print(i)
		break

print(":(")
import math
N=int(input())
x=math.floor(N/1.08)
X=math.floor((N+1)/1.08)
if x < X:
  print(x)
else:
  print(":(")
N = int(input())
for i in range(1,50001):
  tmp = int(i * 1.08)
  if(tmp == N):
    print(str(tmp))
    exit()
print(":(")
n = int(input())

if int(round(n/1.08)*1.08) == n :
    print(round(n/1.08))
else:
    print(":(")
n=int(input())

num=n//1.08

if num*1.08==n:
  print(num)
else:
  print(":(")
# N=1079
N=int(input())

ans=int(round((N*100/108)+0.5))

if round((ans*1.08)+0.5) == N:
    print(ans)
else:
    print(":(")
import math
N = int(input())
if math.floor(int(N/1.08)*1.08) == N*1.08:
  print(N//1.08)
else:
  print(':(')
N = int(input())

import math
import sys

for i in range(1, N):
  cur = math.floor(i * 1.08)
  if cur == N:
    print(i)
    sys.exit()
  if cur > N:
    break
print(":(")
N = int(input())
S = int(N / 1.08)
if S * 1.08 < N or S * 1.08 >= N + 1:
  print(":(")
else:
  print(S)
n = int(input())

if n*100 % 108 == 0:
  print(int(n/1.08))
else:
  print(':(')
import math
N=int(input())
x=math.ceil(N/1.08)
X=math.floor((N+1)/1.08)
if x <= X:
  print(X)
else:
  print(":(")
n = int(input())
can_tax = False
for i in range(1, n):
  if round(i * 1.08) == n:
    x = i
    can_tax = True
    
if can_tax:
  print(x)
else:
  print(":(")
n = int(input())
price = n *25 / 27
p = price.is_integer()
if p == True:
    print(price // 1)
elif p == False:
    print(":(")
import math
N=int(input())
x=math.ceil(N/1.08)
if x == N:
  print(x)
else:
  print(":(")
n = int(input())
n0 = int(n/1.08)

while int(n0 * 1.08) < n:
    n0 += 1

if int(n0 * 1.08) == n:
    print(int(n0 * 1.08))
else:
    print(':(')
N=int(input())
for i in range(50000):
  if i*108//100==N:
    print(i)
  else:
    print(":(")
N = int(input())
if int(N/1.08)*1.08 == N*1.08:
  print(N//1.08)
else:
  print(':(')
N=int(input())

a=N/1080
if int(a*1080)==N:
    print(a)
else:
    print(':(')
n = int(input())
for i in range(1,n):
  if(int(i*1.08) == n):
    print(i)
    exit()
print(":(")
n = int(input())

for i in range(n+1):
    if i * 1.08 == n:
        print(i)
        exit()
print(":(")
n = int(input())
x = n // 1.08
if x * 1.08 == n:
    print(x)
else:
    print(':(')
#B - Tax Rate 
import math
N = int(input())

result = ':('
for i in range(N):
    if math.floor(i * 1.08) == N:#小数点以下切り捨て
        result = i
print(result)
import math
x = int(input())
ans = round(x/1.08)
if x == math.floor(ans * 1.08):
    print(ans)
else:
    print(":(")