peterverebics/CodeNet_Python_118 huggingface dataset:
#!/usr/bin/env python3
#%% for atcoder uniittest use
import sys
input= lambda: sys.stdin.readline().rstrip()
sys.setrecursionlimit(10**9)
def pin(type=int):return map(type,input().split())
def tupin(t=int):return tuple(pin(t))
def lispin(t=int):return list(pin(t))
#%%code
from fractions import gcd
def resolve():
    N=int(input())
    for i in range(N):
        if int(i*1.08)==N:
            print(i)
            return

    print(":(")
#%%submit!
resolve()
import math
N=float(input())
a=math.ceil(N/(1.08))
t=0
for i in range(a,int(N)):
    if math.floor(i*1.08)==N:
        print(a)
        t=t+1
        break
if t==0:
    print(':(')
N = int(input())
 
ans = ":("
for X in range(N-1):
  if N+1 > X * 1.08 > N:
    ans = X
    break
  elif X * 1.08 > N+1:
    break
print(ans)
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()

    for i in range(1, n):
        if int(i*1.08) == n:
            print(i)
            return
    print(":(")

if __name__ == '__main__':
  main()
X = int(input())
ans = X//1.08
if int(ans*1.08) == X:
  print(ans)
elif int((ans+1)*1.08) == X:
  print(ans+1)
else:
  print(':(')
import math as math

x = int(input())

N = math.floor(x/1.08)
if N*1.08 == x:
    print(N)
    
else:
    print(":)")
from math import floor

def main():
    N=int(input())
    for i in range(1,N):
        if floor(i*1.08) == N:
            print(i)
            exit()
    print(':(')

main()
N = int(input())
for i in range(1,101):
  tmp = int(i * 1.08)
  if(tmp == N):
    print(str(tmp))
    exit()
print(":(")
# N=1079
N=int(input())

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

if a+1 <b:
    print((a+0.9999999999999999999999999999)//1)
else:
    print(":(")
n = int(input())
rate = 1.08
api = round(n / rate)
if n == int(api * rate):
    print(api)
else:
    print(":(")
n = int(input())
x = n // 1.08
if int(x * 1.08) == n:
    print(x)
else:
    print(':(')
n = int(input())
for i in range(n):
    ans = int(i*1.08)
    if ans == n:
        print(i)
        break
else:
    print(":(")
# N=1079
N=int(input())

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

if round((ans*1.08)) == N:
    print(ans)
else:
    print(":(")
# 三井住友信託銀行プログラミングコンテスト2019: B – Tax Rate
N = int(input())

X = int(N / 1.08)
X_min = int(X * 1.08)
X_max = int((X + 1) * 1.08)

print(X, X_min, X_max)

if X_min == N:
    print(X)
elif X_max == N:
    print(X + 1)
else:
    print(':(')
N = int(input())
 
for i in range(1, N):
  if i + (i * 8) // 100 == N:
    print(i)
    break
else:
  print(":(")
# N=1079
N=int(input())

ans=int(round((N/1.08)+0.1))

if ((ans*1.08)+0.01)//1 == N:
    print(ans)
else:
    print(":(")
import sys
input = sys.stdin.readline

N = int(input())

p=N/1.08
if(p%1==0):
	print(int(p))
else:
	if((int(p)+1*1.08)!=N):
		print(":(")
	else:
		print(int(p)+1)
n=int(input())
num=round(n/1.08)
check=round(num*1.08)
if check==n:
    print(num)
else:
    print(':(')
n = int(input())

x = int(round(n/1.08))

if int(x*1.08) != n:
    print(':(')
else:
    print(x)
n = int(input())
can_tax = False
for i in range(1, n):
  if int(i * 1.08) == n:
    x = i
    can_tax = True
    
if can_tax:
  print(x)
else:
  print(":(")
N=int(input())
S=-(-N//1.08)
if S*1.08==N:
  print(int(S))
else:
  print(":(")
import math
N = int(input())
for i in range(N) :
    if math.floor(i * 1.08 ) == N :
        print(i)
        exit()


print(':(')
# B - Tax Rate
def main():
    N = int(input())
    x = N / 1.08
    print(int(x) if x.is_integer() else ":(")


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

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

price = n / 1.08
if math.floor(round(price) * 1.08) == n:
    print(round(price))
else:
    print(':(')
N=int(input())

a=N/1.08
if int(a*1.08)==N:
    print(a)
else:
    print(':(')
import math

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

if (n + 1) % 108 == 0:
    print(':(')
else:
    if n % 108 == 0:
        print(n // 108 * 100)
    else:
        print(int(n // 1.08 + 1))
import math
def taxminus(X):
    return X/1.08,(X+1)/1.08
N=int(input())
min,max=taxminus(N)
min=math.ceil(min)
if min>max:
    print(":(")
else:
    print(min)
#4
import sys
N = int(input())
x,y,k = 0,0,0

if N == 1:
    print(1)
    sys.exit()

x = int(0.8*N)

for i in range(x,N):
    k = str(i*108)
    if int(k[0:-2]) == N:
        print(i)
        y +=1
        break

if y !=1:
    print(":(")
import sys
n = int(input())
for i in range(n):
    if int(i*1.08) == n:
        print(i)
        sys.exit()

print(":(")
n = int(input())
for i in range(50000):
    x = int(i * 1.08)
    if (n == x):
        print(float(i))
        exit()
print(':(')
n = int(input())
for i in range(n):
    if int(i*1.08) == n:
        print(i)
        exit()
print(":(")
X = int(input())

for i in range(50000):
  if int(i*1.05) == X:
    print(i)
    break
else:
  print(':(')
#B - Tax Rate 
import math
N = int(input())

result = ':('
for i in range(1,N):
    if math.floor(i * 1.08) == N:#小数点以下切り捨て
        result = i
print(result)
import math

N = int(input())
ans = int(math.ceil(N / 1.08) * 1.08)
if N == ans:
    print(ans)
else:
    print(":(")
N = int(input())
X = -(-N//1.08)
n = X*108//100
if(int(N)==int(n)):
  print(X)
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(i)
        exit(0)
print(":(")
n=int(input())
a,b=int(n/1.08),int((n+1)/1.08)
if b-a==1:
  print(b)
else:
  print(":(")
N = int(input())
flag = True
for i in range(N):
  if int(i * 1.08) == N:
    print(i)
    flag = False
    break
if flag:
  print(":(")
N = int(input())
ans=-1

for i in range(1,N+1):
       if int( i*1.08)==N:
            ans = i
            
if ans == -1:
    print(':(')
else:
    print(i)
N=float(input())
x=N//1.08
if x*1.08<=N<=(x+1)*1.08:
  print(x)
else:
  print(':(')
n = int(input())
f = 0
for i in range(n):
  if int(i*1.08) == n:
    print(i)
    f = 1
if f == 0:
  print(':(')
import math
N = int(input())
X = round(N / 1.08)

#再計算
if math.floor(1.08 * X) == N:
    print(X)
else:
    print(":(")
import math
import sys
N = int(input())
ans = 1
while ans < N:
    if(math.floor(ans * 1.08) == N):
        print(ans)
        sys.exit()
    else:
        ans += 1
print(":(")
N=float(input())
x=int(N/1.08)
if N<=(x+1)*1.08<=N+1: 
  print(x+1)
elif N<=x*1.08<=N+1:
  print(x)
else:
  print(':(')
N = int(input())
X = N//1.08-1
while True:
    if int(X*1.08) == N:
        print(int(X))
        exit()
    elif int(X+1.08) < N:
        X += 1
    else:
        print(':(')
        exit()
n = int(input())
for i in range(int(n/1.08), int(n/1.06)):
    if int(i*1.08)==n:
        print(i)
        break
else:
    print(':(')
import math
N = int(input())
zeinuki = math.floor(N / 1.08)
print(':('if N != math.floor(zeinuki * 1.08) else zeinuki)
import sys
import math

input = sys.stdin.readline

def main():
    b = True
    n = int(input())
    for i in range(n):
        if math.floor(i * 1.08) == n:
            print(i)
            b = False
            break
    if b:
      print(':(')

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

ans_bool = False
ans_num = 0

for i in range(0, n):
    if math.floor(i * 1.08) == n:
        ans_bool = True
        ans_num = i
    else:
        pass
if ans_bool:
    print(ans_num)
else:
    print(":(")
n=int(input())
x=round(n/1.08)

if int(x*1.08)==n:
    print(x)
else:
    print(':(')
n = int(input())

n_1 = n + 1

s = int(n // 1.08)
t = int(n_1 // 1.08)
if s % 1.08 == 0:
    print(s)
elif s != t:
    print(t)
else :
    print(':(')
n=int(input())
a=n//1.08
b=int(a*1.08)
if a==b:
  print(a)
else:
  print(":(")
N = int(input())

x = int(N / 1.08)

if int(x * 1.08) == N:
  print(x)

elif int((x+1)*1.08) == N:
    print(x+1)

elif int((x-1))*1.08 == N:
    print(x-1)
  
else:
  print(':/')
import math

n = int(input())

if int(math.ceil(n/1.08)*1.08) == n or int(math.floor(n/1.08)*1.08) == n:
    print(round(n/1.08))
else:
    print(":(")
import math
n=int(input())
x=math.ceil(n/1.08)
nn=n*1.08
if math.floor(nn)==n:    
	print(x)
else:
  print(":(")
import math
N = int(input())

for i in range(math.floor(N/1.08),N):
  if math.floor(i*1.08) == N:
    print(i)
    exit()
print(':(')
n = int(input())
zeibatu = int(n / 1.08)
zeikomi = int(zeibatu * 1.08)
if n == zeikomi:
    print(zeibatu)
else:
    print(":(")
x = int(input())
ans = round(x/1.08)
if x == round(ans * 1.08):
    print(ans)
else:
    print(":(")
n = int(input())

for i in range(50001):
	if int(i * 1.08) == n:
		print(int(i))
		exit()
	else:
		print(":(")
N = int(input())

ans = 0
for i in range(N - int(N/10), N + int(N/10)):
    if int(i*1.08) == N:
        ans = i
        break

if ans != 0:
    print(ans)
else:
    print(":(")
N = int(input())

senter = N // 1.08

for i in range(1000):
    if senter-100+i == N:
        print(senter-100+i)
        break
    else:
        print(":(")
n=int(input())
for i in range(n):
  if int(i*1.08)==n:
    print(i)
    break
else:
  print(":(")
# -*- coding: utf-8 -*-

# N円の候補を羅列
N_list = list()
for n in range(1,50000):
    if(n*1.08 <= 50000):
        #小数点切り捨て
        N_list.append(int(n*1.08))
    else: break

# N円の支払い (1 ≤ N ≤ 50000)
N = int(input())
#N = 432
count = 0
for n in N_list:
    if(n == N):
        count = count + 1
    else: count = count

# 税抜き価格
if(count == 1): print(int(round(N/1.08)))
else: print(':(')
n = int(input())
can = False
for i in range(1, n + 1):
    if(i * 1.08 == n):
        print(i)
        can = True
        break
if(can == False):
    print(":(")
n = int(input())

x_min = int(n / 1.08)
x_min_mod = (100 * n) % 108
x_max = int((n + 1) / 1.08)
x_max_mod = (100 * (n + 1)) % 1.08

if x_min_mod == 0:
    print(x_min)

elif not x_max_mod == 0 and x_max - x_min > 0:
    print(x_max)

elif x_max_mod == 0 and x_max - x_min > 1:
    print(x_max - 1)

else:
    print(':(')
import math
n = int(input())
x = math.ceil(n / 1.08)
if x * 1.08 == n:
  print(x)
else:
  print(":(")
from math import floor
from decimal import Decimal
n = int(input())
tax = Decimal("1.08")
for i in range(1,n):
    if floor(Decimal(str(i))*tax) == n:
        print(i)
        break
else:
    print(":(")
n = int(input())
if 0<=(n%100) % 8<=4:
  print((round(n*(100/108))))
elif (n%100) % 8 == 0:
  print(int(n*(100/108)))
elif (n%100) % 8 >4:
  print(':(')
n = int(input())
for x in range(1, 50005):
    if x * 1.08 == n:
        print(x)
        exit()
else:
    print(':(')
N = int(input())
for X in range(int(N/1.1), N):
    if int(X * 1.08) == N:
        print(X)
        exit()
print(":(")
import math
N = int(input())
for i in range(1,N):
    if math.floor(i*1.08) == N:
        print(i)
        break
else:
    print(":(")
n=int(input())
x=round(n*100/108)
if n==round(x*1.08):
	print(x)
else:
	print(':(')
N = int(input())
for i in range(int(N * 0.9), N):
    if int(i * 1.08) == N:
        print(i)
        break
else:
    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)
import math
import sys
readline = sys.stdin.readline


def main():
    n = int(readline().rstrip())

    for i in range(50001):
        k = math.floor(i * 1.08)
        if n == k:
            print(i)
            break


if __name__ == '__main__':
    main()
import math
import sys
N = int(input())
for i in range(N) :
    if math.floor(i * 1.08 ) == N :
        print(i)
        sys.exit()

print(':(')
n=int(input())
x=int(n/1.08)
if(n*100-round(1.08*x*100)<1):
    print(x)
else:
    print(":(")
import math
n = int(input())
ans = n*100/108
if ans.is_integer(): print(int(math.ceil(ans)))
else: print(':(')
N=int(input())

ans=int(round((N/1.08)+0.1))

if (ans*1.08)//1 == N:
    print(ans)
else:
    print(":(")
import sys
import math

input = sys.stdin.readline

def main():
    _is_found = False
    n = int(input())
    for x in range(n):
        if math.floor(x * 1.08) == n:
            print(x)
            _is_found = True
            break
    if _is_found:
      print(':(')

if __name__ == '__main__':
    main()
import math
N=int(input())
X=N/1.08
X=math.ceil(X)
if X*1.08==N:
  print(X)
else:
  print(":(")
n = int(input())

import math

x = n / 1.08
m = math.floor(n * 1.08)

if m == n:
    print(x)
else:
    print(':(')
import math
N =  int(input())

a = N/1.08
b = (N+1)/1.08

if b-math.ceil(a) < 0:
    print(':(')
else:
    print(math.ceil(a))
a = int(input())
b = int(a/1.08)
c = b + 1
d = int(b * 1.08)
e = int(c * 1.08)
if d == a:
  print(d)
elif e == a:
  print(e)
else:
  print(':(')
n=int(input())
for m in range(int(n//1.1),int(n)):
	if int(m*1.08)==n:
		print(m)
		break
else:print(":(")
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
        if xx==n100:
            print(x)
            break
    else:
        print(':(')

        

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

xmin = int(n/1.08)
xmax = int((n+1)/1.08)


if n%27 == 0:
  print(xmax)
elif (n+1)%27 == 0:
  print(xmin)
elif xmin == xmax:
  print(":(")
else:
  print(xmax)
N = int(input())

est_X = int(N/1.08)*1.08

if est_X == N:
    print(est_X)
elif est_X + 1 == N:
    print(est_X + 1)
else:
    print(':(')
N=int(input())

ans=round((N/1.08)+0.01)

if round((ans*1.08)+0.01)==N:
    print(ans)
else:
    print(":(")
n = int(input())
for x in range(int(n / 1.1), n):
    if int(x * 1.08) == n:
        print(x)
        exit(0)
print(':(')
X = int(input())

if X % 1.08 == 0:
    print(X//1.08)
else:
    if int((int(X//1.08)+1) * 1.08) == X:
        print(X//1.08+1)
    else:
        print(":(")
n = int(input())

for i in range(1,n):
  txd = int(i*1.08)
  if n==txd:
    print(i)
    exit()
print(":(")
def II(): return int(input())
def MI(): return map(int,input().split())
def LMI(): return list(map(int,input().split()))
def LIIN(n): return list(int(input()) for _ in range(n))
def LMIN(n): return [list(map(int, input().split())) for _ in range(n)]
def IS(): return input()
def LS(): return list(input())
def MS(): return map(str,input().split())
def LMS(): return list(map(str,input().split()))
def LMS(): return list(map(str,input().split()))
def LISN(n): return list(input() for _ in range(n))
def LMSN(n): return [input().split() for _ in range(n)]
MOD = 10**9+7
INF = 10**18

def main():
    n = II()
    print(n*100//108)

if __name__ == '__main__':
    main()
import sys
N = int(input())
for n in range(1, N):
    if int(n * 1.08) == N:
        print(n)
        sys.exit()
print(":(")
import math
n=int(input())
if (n/1.08).is_integer():
    print(int(n/1.08))
else:
    print(":(")
import numpy

N = int(input())
X0 = N / 1.08
X1 = (N + 1) / 1.08

if numpy.floor(X0) * 1.08 == N:
    print(int(numpy.floor(X0)))
elif numpy.floor(X1) - numpy.floor(X0) == 0:
    print(':(')
else:
    print(int(numpy.floor(X0) + 1))
n= int(input())
ans=":("

for k in range(n):
  if int(k*1.08)==n:
    ans=k
    
print(ans)
# N=1079
N=int(input())

a=int(N*100/110)-1

flg=False

for i in range (N-a+1):
    if ((a+i)*1.08)//1==N:
        print(a+i)
        exit
    else:
        pass
print(':(')
n = int(input())
x = n / 1.08
if round(x * 1.08) == n:
  print(x)
else:
  print(":(")
N = int(input())

x = N // 1.08

if x*1.08 < N:
  print(":(")
else:
  print(x)
N = int(input())
 
if N*100%108 != 0:
  print(":(")
else:
  print(int(N/1.08))
import math
N = int(input())
flag = True
for i in range(N):
    if math.floor(i * 1.08) == N:
        print(i)
        flag = False
        break
if flag:
    print(':(')
import math

n = int(input())

m = (n+1)//1.08
l = math.floor(m*1.08)

if m==l:
    print(m)
else:
    print(":(")
import math

n = int(input())

for i in range(n):
    if (i * 108 //100 == n):
        print(i)
        break
else:
    print(":(")
import math
N = int(input())

f = N // 1.1

ok = False
while True:
  n = math.ceil(f * 1.08)
  if n == N:
    ok = True
    break
  elif N < n:
    break
    
  f += 1
  
if not ok:
  print(':(')
else:
  print(n)
import math
N = int(input())
ans = ""
for i in range(1, N):
  if math.floor(i * 1.08) == N:
    ans = i
    break
print(ans if ans != "" else ":(")
import math

n = int(input())

for i in range(n):
    if (math.floor(i * 1.08) == n):
        print(i)
        break
else:
    print(":(")
import collections
import sys
import numpy as np
sys.setrecursionlimit(1000000000)
from heapq import heapify,heappop,heappush,heappushpop
MOD = 10**9+7
import itertools
import math

n = int(input())
ans = n/1.08
ans = round(ans)
temp = int(ans*1.08)
if temp == n:
    print(ans)
else:
    print(":(")
import math
n = int(input())
a = math.ceil(n/1.08)

if a*1.08 >= n:
  print(a)
else:
  print(':(')
  print(a)
n = int(input())
if (len(str(n/1.08).split('.')[1])) <= 3:
    print(round(n/1.08))
else:
    print(":(")
# sumitb2019_b.py
import math
N = int(input())
for i in range(N):
    if math.floor(i*1.08) == N:
        print(i)
        exit()
print(":(")
n = int(input())
n0 = int(n/1.08)-1

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(N):
	if i*1.08==N:
		print(i)
		exit()
print(":(")
import math
n=int(input())
x=n/1.08
nn=x*1.08
if math.floor(nn)==n:    
	print(math.ceil(x))
else:
  print(":(")
n = int(input())

from decimal import Decimal

import sys

for i in range(60000):
    if Decimal(i) * Decimal('1.08') == n:
        print(i)
        sys.exit()

print(':(')
N = int(input())
if int(round(N / 1.08) * 1.08) == N: 
    print(int(N / 1.08))
else:
    print(':(')
n = int(input())
f = 0
for i in range(n):
  if int(i*1.08) == n:
    print(i)
    exit()
print(':(')
#三井住友信託銀行2019-B
import math
n = int(input())

result_int = round(n / 1.08)

if math.floor(result_int * 1.08) == n:
    print(result_int)

else:
    print(':(')
N = int(input())
for i in range(1, N):
  if int(i*1.08) == N:
    print(i)
    quit()

print(':(')
n = int(input())
x = n / 1.08
ans = int(x+0.5) * 1.08
if int(ans) == n:
    print(int(x+0.5))
else:
    print(":(")
n = int(input())

x = round(n / 1.08)

if int(x * 1.08) == n:
  print(x)
else:
  print(":(")
N=int(input())
x=N//1.08
if int(x*1.08) == N:
  print(x)
elif int((x+1)*1.08) == N:
  print(x+1)
else:
  print(':(')
# N=1079
N=int(input())

ans=int(round((N*100/108)+0.1))

if (ans*1.08)//1 == N:
    print(ans)
else:
    print(":(")
import sys
n = int(input())

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

print(":(")
import math
n=int(input())
print(math.ceil(n/1.08))
n = int(input())

dic = {}
for i in range(1,5000):
    dic[int(i * 1.08)] = i
#print(dic)

if n in dic:
    print(dic[n])
else:
    print(':(')
import sys
import math
n = int(input())
for i in range(n):
    if math.floor(i*1.08) == n:
        print(i)
        sys.exit()

print(":(")
import math
n=int(input())
for i in range(n):
    if math.floor(i*1.08)==n:
        print(i)
        break
    elif i*1.08>n:
        print(":(")
        break
N = int(input())
S = int(N/1.08)
a = []

for i in range(1,50001):
  a.append(int(i*1.08))
  
if N in a:
  print(S)
else:
  print(":(")
n=int(input())
a,b=int(n/1.08),int((n+1)/1.08)
if float(n/1.08)-int(n/1.08)==0:
  print(a)
elif b-a==1:
  print(b)
else:
  print(":(")
def solve(n):
  for i in range(50000):
    x = i + 1
    if int(x * 1.08) == n:
      return x
    
  return -1
  

  
N = input()
ans = solve(N)
print(":(" if ans == -1 else ans)
# N=1079
N=int(input())

ans=int(round((N*100/108)+0.1))

if round((ans*1.08)) == N:
    print(ans)
else:
    print(":(")
n=int(input())
x=n/1.08
nn=x*1.08
if n<=nn<n+1:
	if x*10%10>=5:    
		print(int(x)+1)
	else:
		print(int(x))
else:
  print(":(")
n = int(input())
found = False

for i in range(n):
    x = int ( i * 1.08 )
    if x == n :
        print(i)
        found = True
        break

if not found:
    print(":(")
N = int(input())
for i in range(N):
    if int(i * 1.08) == N:
        print(i)
        break
else:
    print(':(')
N = int(input())

x = int(N / 1.08)

if int(x * 1.08) == N:
  print(x)

elif int((x+1)*1.08) == N:
    print(x+1)

else:
  print(':/')
import math

n = int(input())

for i in range(n):
    if (math.floor(i * 1.08) == n):
        print(i)
else:
    print(":(")
N=int(input())

a=int(N*100/110)-1

flg=False

for i in range (N-a):
    if (a*1.08)//1==N:
        print(a+i)
        exit
    else:
        pass
print(':(')
n = int(input())

for i in range(n + 1) :
	if int(i * 1.08) == n:
		print(i)
		break
	else:
		print(":(")
N = int(input())
X = N/1.08

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

origin = int(n * 100 / 108)
if int(origin * 108 / 100) != n:
  print(":(")
else:
  print(origin)
import math
N = int(input())
A = N/1.08 
B = math.floor(A)
Ans = B*1.08
Ans2 = (B+1) * 1.08
if Ans == N:
  print(B)
elif Ans2 == N:
  print(B+1)
else:
  print(':(')
pay=int(input())
price=pay/1.08
price=round(price)
#print(price)
if int(price*1.08)==pay:
    print(price)
else:
    print(':(')
import math
n = int(input())
x1 = math.ceil(n/1.08)
x2 = (n+1)/1.08
print(':(' if x2<x1 else x1)
N = int(input())
for x in range(N):
    if int(x*1.08) == N:
        print(x)
        exit()
print(":(")
N = int(input())
 
ans = ":("

for X in range(N-1):
  if N+1 > X * 1.08 >= N:
    ans = X
    break
  elif X * 1.08 >= N+1:
    break
  else:
    continue
    
print(ans)
N = int(input())

N_ = round((N/1.08//1)*1.08//1)

if N == N_:
    print(round((N/1.08//1)))

else:
    print(":(")
import math
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(1,50001):
    if i*1.08==n:
        print(i)
        exit()
print(":(")
from decimal import Decimal, ROUND_HALF_UP, ROUND_HALF_EVEN

N = int(input())

if N < 13:
  print(':(')

X = N / 1.08
X = Decimal(str(X)).quantize(Decimal('0'), rounding=ROUND_HALF_UP)
X = int(X)

if N == int(X * 1.08):
  print(X)
else:
  print(':(')
import math

n = int(input())
for i in range(n):
    ans = math.ceil(i * 1.08)
    if ans == n:
        ans = i
        break
    else:
        ans == ":("
print(ans)
N = int(input())
 
ans = ":("
for X in range(N-1):
  if N+1 > X * 1.08 >= N:
    ans = X
    break
  elif X * 1.08 >= N+1:
    break
print(ans)
N=int(input())

a=round(N/1.08)
if int(a*1.08)==N:
    print(a)
else:
    print(':(')
a=int(input())
b=0
for i in range(a):
  c=i
  c+=(i*8)//100
  if c==a:
    b=i
print(":("if b==0 else b)
import math
n = int(input())
a = math.ceil(n/1.08)
b = math.floor((n+1)/1.08)
print(a*(a == b) or ":(")
# N=1079
N=int(input())

ans=round((N/1.08)+0.001)

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

x1 = int(N/1.09)
x2 = int(N/1.07)

for x in range(x1, x2):
    if int(x*1.08) == N:
        print(x)
        break
else:
    print(':(')
import math
N = int(input())
for i in range(1,50001):
    if math.floor(i*1.08) == N:
        print(i)
    else:
        print(":(")
N = int(input())

for i in range(1, N):
  if i + i * 8 // 100 == N:
    print(i)
else:
  print(":(")
N = int(input())
S = N / 1.08
if int(S) * 1.08 != N:
  print(":(")
else:
  print(int(S))
N=int(input())

for i in range(N):
    if int(i*1.08)==N:
        print(i)
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 = 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(1, N):
    if int(i*1.08) == N:
        print(i)
        break
else:
    print(":(")
# N=1079
N=int(input())

ans=int(round((N/1.08)+0.1))

if (ans*1.08)//1 == N:
    print(ans)
else:
    print(":(")
N = int(input())
n = 0
import math
for i in range(1, N):
    if math.floor(i*1.08) == N:
        print(i)
        n = 1
        break
if n ==0 :
    print(':(')