peterverebics/CodeNet_Python_118 huggingface dataset:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)

n = int(input())

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

ans = bs(n, 0, lambda x: x * 1.08 >= n)
if ans * 1.08 == n:
    print(ans)
else:
    print(':(')
import math

N = int(input())

lower = N / 1.08
upper = (N + 1) / 1.08

vl = math.ceil(lower)
vu = math.floor(upper)

if vl < upper:
  print(vl)
  exit(0)
if lower <= vu:
  print(vu)
  exit(0)
else:
  print(":(")
N = int(input())
n = 0
for i in range(N-int((N*0.08)), N):
    
    if int(i*1.08) == N:
        print(i)
        n = 1
        break
if n ==0 :
    print(':(')
import math
N = int(input())
S = math.ceil(N / 1.08)
if S * 1.08 != N:
  print(":(")
else:
  print(S)
n = int(input())
value = round(n/1.08)
print(value if value != n//1.08 else ':(')
import sys
N = int(input())
for n in range(N*100//108,N):
  if n*1.08//1 == N:
    print(n)
    sys.exit()
print(":(")
N = int(input())
X = N//1.08 +1
x = N//1.08
y = N//1.08 -1

if X*1.08 //1 == N:
  print(X)
elif x*1.08//1 == N:
  print(x)
elif y*1.08//1 == N:
  print(y)
else:
  print(":(")
# import math

N = int(input())

# of = math.floor(N / 108 * 100)
# oc = math.ceil(N / 108 * 100)
o = round(N / 108 * 100)

# if(int(of * 108 / 100) != N and int(oc * 108 / 100) != N):
if round(o * 108 / 100) != N:
    print(":(")
else:
    print(o)
N=int(input())
X=N/1.08
if X==int(X):
    print(int(X))
elif int(X*1.08)!=N:
    print(":(")
else:
    print(int(X)+1)
import math
N=int(input())
s=N/1.08
s=math.ceil(s)
print(s)
N = int(input())

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

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


if n % 27 != 0 and xmin == xmax:
  print(":(")
else:
  print(xmax)
N = int(input())
x = N // 1.08
M = x * 1.08 // 1
if N == M:
  print(x)
else:
  print(':(')
n = int(input())
can_tax = False
for i in range(1, n):
  if round(i * 1.08) == n:
    x = round(i * 1.08)
    can_tax = True
    
if can_tax:
  print(x)
else:
  print(":(")
N = int(input())

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

solve(N)
N = int(input())
flag = True
for i in range(1,10000):
  if int(i * 1.08) == N:
    print(i)
    flag = False
    break
if flag:
  print(":(")
x = int(input())
y = round(x / 1.08)
if int(y * 1.08) == x:
  print(y)
else:
  print(':(')
import math


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


if __name__ == "__main__":
    solve()
import math
def resolve():
    n=int(input())
    x=-(-n//1.08)
    
    if n==math.floor(x*1.08):
        print(x)
    else:
        print(':(')
resolve()
N = int(input())
X = N//1.08
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())
a = int(N / 1.1)
for i in range(a - 1, N):
    if N == int(i * 1.08):
        print(i)
#4
N = int(input())
x,y = 0,0

x = int(0.8*N)

for i in range(x,N):
    if int(i*1.08) == N:
        print(i)
        y +=1
        break

if y !=1:
    print(":(")
import math

n=int(input())

num=round(n/1.08)

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

if x//1*1.08//1 == N:
  print(x//1)

else:
  print(":(")
from decimal import Decimal
import math

n = int(input())

n_1 = n + 1

s = Decimal(n / 1.08)
t = Decimal(n_1 / 1.08)
print(s)
print(t)

if math.floor(s) != math.floor(t):
    print(round(t))
else :
    print(':(')
n = int(input()) * 100

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

if x_min_mod == 0:
    print(int(x_min / 100))

elif not x_max_mod == 0 and x_max - x_min > 0:
    print(int(x_max / 100))

elif x_max_mod == 0 and x_max - x_min > 100:
    print(int(x_max / 100 - 1))

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)
    for x in range(x9,x7+1):
        if int(x*1.08)==n:
            print(x)
            break
    else:
        print(':(')

        

if __name__=='__main__':
    n=readinput()
    main(n)
N=int(input())
S=float(N/1.08)
if S%1==0:
  print(S)
else:
  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 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
f = True
N = int(input())
for i in range(N):
    if math.floor(i*1.08) == N:
        print(i)
        f = False
        break
if f:
    print(":(")
import math
n=int(input())
x=round(n/1.08)
if(math.floor(1.08*x)==n):
    print(x)
else:
    print(":(")
import math

N = int(input())

a = math.floor(N / 1.08)
b = a + 1

aa = math.floor(a * 1.08)
bb = math.floor(b * 1.08)

if(aa == N):
    print(aa)
else:
    if(bb == N):
        print(bb)
    else:
        print(":(")
N = int(input())
import math
X = math.floor(N/1.08)
if N == math.ceil(X*1.08):
 print(X)
else:
 print(':(')
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(i)
        t=t+1
        break
if t==0:
    print(':(')
n=int(input())
for i in range(50000):
	if n==int(i*1.08):
		print(i)
	elif i==49999 and n!=int(i*1.08):
		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 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())

x = int(n/1.08)
x2 = int((n+1)/1.08)

if x<=n<x2:
    print(':(')
else:
    print(x2)
import math
n = int(input())
price = math.floor(n / 1.08 )
if price * 1.08 == n:
    print(price)

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
      break
    
    
if ans == 0:
  print(':(')
import math

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

for i in range(N):
    if int(i*1.08)==N:
        print(i)
        break

if all(int(i*1.08)!=N for i in range(N))==True:
    print("No")
N = int(input())

X = N / 1.08
if X.is_integer():
    print(int(X))
else:
    print(':(')
a = int(input())
b = a / 1.08
a = int(a/1.08)
if b == a:
  print(a)
else:
  print(':(')
#!/usr/bin/env python
# coding: utf-8

# In[18]:


N = int(input())


# In[23]:


for x in range(int(N * 10/11), N):
    if x*1.08//1 == N:
        print(x)
        break
else:
    print(":(")


# In[ ]:
import math

n = int(input())
plice = math.floor(n / 1.08)
can_tax = False
for i in range(1, plice):
  if int(i * 1.08) == n:
    x = i
    can_tax = True
    
if can_tax:
  print(x)
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 not _is_found:
        print(':(')

if __name__ == '__main__':
    main()
import sys
n = int(input())
if n == 1:
    print(":(")
    sys.exit()
for i in range(1,n+1):
    if int(i*1.08) == n:
        print(i)
        sys.exit()

print(":(")
N=int(input())

ans=round(N/1.08)
if round(ans*1.08)==N:
    print(ans)
else:
    print(":(")
N = int(input())
for x in range(N):
    if int(x*1.08) == N:
        print(x)
        exit()

print(':(')
n = int(input())
ans = -1
for x in range(n):
    tmp = int(x*1.08)
    if tmp == n:
        ans = x
        break

if ans == -1:
    print(":(")
else:
    print(ans)
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())
S=int(round(N/1.08,0))
if (S*1.08)//1==N:
    print(S)
else:
    print(':(')
import math
x = int(input())
ans = math.ceil(x/1.08)
if x == round(ans * 1.08):
    print(ans)
else:
    print(":(")
import math

N=int(input())

for i in range(N):
	if math.floor(i*1.08)==N:
		print(i)
		exit()
print(":(")
import math
N=int(input())
a=math.ceil(N/(1.08))
for i in range(a,N):
    if i==N:
        print(a)
        break
    else:
        print(':(')
import numpy as np


N = int(input())

X = int(np.round(N/1.08))

if np.floor(X*1.08)!=N:
    X = ':('

print(X)
s=int(input())
n = int(s/1.08)
print(n)
for i in range(n):
    if int(n*1.08)==s:
        print(n)
        break
    elif int(n*1.08)<s:
        n+=1
        continue
    else:
        print(":(")
        break
n = int(input())
v = int(n//1.08)+1
if int(v*1.08) == n:
    print(v)
else:
    print(':)')
n = int(input())

import math

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

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

if n%(108/100)==0:
  print(n*(100/108))
else:
  print( ':(' )
n = int(input())

origin = int(n * 100 / 108)
if origin * 108 / 100 != n:
  print(":(")
else:
  print(origin)
import sys
N = int(input())
for n in range(N*100//109,N):
  if n*1.08//1 == N:
    print(n)
    sys.exit()
print(":(")
import math

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

n = int(input())
x = math.ceil(n / 1.08)

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

for i in range(50000):
 if int(i*1.08)== n:
  print(i)
  break
 else:
  print(':(')
  break
n = int(input())
ans = int(n*100/108)
if int(ans*1.08)==n:
    print(ans)
elif int((ans-1)*1.08)==n:
    print(ans-1)
elif int((ans-1)*1.08)==n:
    print(ans+1)
else:
    print(":(")
import math

N=int(input())

for i in range(1,N):
	if math.floor(i*1.08)==N:
		print(i)
		exit()
print(":(")
N = int(input())
 
ans = ":("
for X in range(1, N):
  if N+1 > X * 1.08 >= N:
    ans = X
    break
  elif X * 1.08 > N+1:
    break
print(ans)
import math
n=int(input())
x=int(n/1.08)
if(math.floor(1.08*x)==n):
    print(x)
else:
    print(":(")
N = int(input())
if N * 25 / 27 % 1 == 0:
  print(int(N * 25 / 27))
elif N * 25 / 27 % 1 >= 0.5:
  print(int(N * 25 / 27 + 1))
else:
  print(":(")
import math


def solve():
    N = int(input())
    if round(math.ceil(N / 1.08) * 1.08) == N:
        print(math.ceil(N / 1.08))
    else:
        print(':(')


if __name__ == "__main__":
    solve()
import math

n = int(input())
plice = math.floor(n / 1.08)

for i in range(1, plice):
  if math.floor(i * 1.08) == n:
    print(i)
    exit()

print(":(")
N = int(input())

X = int(N / 1.08)
print(X if int(X * 1.08)==N or int((X+1)*1.08==N) else ':(')
n = int(input())
around = int(n*0.8)
for i in range(around,n):
  txd = int(i*1.08)
  if n==txd:
    print(i)
    exit()
print(":(")
N = int(input())

if (N*100)%108 != 0:
    print(":(")
else:
    print(int(N/1.08))
import sys
n = int(input())
if n == 1:
    print(":(")
    sys.exit()
for i in range(n):
    if int(i*1.08) == n:
        print(i)
        sys.exit()

print(":(")
from math import floor

n = int(input())

x = round(n/1.08)
y = floor(x * 1.08)

print(x if n == y else ':(')
N = int(input())

mini = N / 1.08
maxx = (N + 1) / 1.08
int_n = int((N + 1) / 1.08)

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

print(ans)
import math

n = int(input())

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

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

if int((ans*1.08)+0.01)==N:
    print(ans)
else:
    print(":(")
#B
import math
n=int(input())
ans=None
for i in range(1,n):
    if math.floor(i*1.08)==n:
        ans=i
        break
    if i==n-1:
        ans=":("
print(ans)
import math
N = int(input())
X = math.floor(N/1.08)
if N == math.ceil(X*1.08):
 print(X)
else:
 print(':(')
import math as math

x = int(input())

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

n = int(input())

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

if n==l:
    print(m)
else:
    print(":(")
import math
N = int(input())
if math.floor(N/1.08)*1.08 == N:
  print(int(N/1.08))
else:
  print(':(')
from math import floor

def main(N, rate=1.08):
    ans = -1
    for x in range(1, N+1):
        if floor(x * 1.08) == N:
            ans = x
    return ans


if __name__ == "__main__":
    N = int(input())
    ans = main(N)
    print(ans if ans > 0 else ':)')
def main():
    N = int(input())
    for i in range(N):
        ans = i * 108 // 100
        if ans == N:
            print(i)
            return
    print(':(')

main()
# N=1079
N=int(input())

ans=(N/1.08)//1

if (ans*1.08)//1 == N:
    print(ans)
else:
    print(":(")
import math
n=int(input())
for i in range(1,46000):
  if math.floor(i*1.08)==n:
    print(i)
    break
  else:
    continue
else:
  print(":(")
n = int(input())
if n%1.08==0:
  print(n//1.08)
else:
  x_init=n//1.08 + 1
  x_n = int(1.08*x_init)
  if x_n ==n:
    print(x_init)
  else:
    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)
    if int(x * 1.08) == n:
        print(x)
    else:
        print(":(")

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

for i in range(math.ceil(N/1.08),N):
  if math.floor(i*1.08) == N:
    print(i)
    exit()
print(':(')
N = int(input())

for x in range(N):
    if int(x*1.08) == N:
        print(x)
        break
else:
    print(':(')
N = int(input())

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

if X*1.08 //1 == N:
  print(X)
else:
  print(":(")
n=int(input())
ans=n/1.08+0.5
if int(int(ans)*1.08)==n:
  print(int(ans))
else:
  print(':(')
# N=1079
N=int(input())

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

if ((ans*1.08)+0.1)//1 == N:
    print(ans)
else:
    print(":(")
n = int(input())
for i in range(n):
  if i * 1.08 == n:
    print(i)
    exit()
print(":(")
n = int(input())

for x in range(n):
    if int(x * 1.08) == n:
        print(x)
        break
else:
    print(':(')
n = int(input())
x = int(n/1.08)

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

if X*1.08 //1 == N:
  print(X)
elif x*1.08//1 == N:
  print(x)
else:
  print(":(")
import math
n=int(input())
x=n/1.08
nn=x*1.08
if n<=nn<n+1:    
	print(math.ceil(x))
else:
  print(":(")
n = int(input())

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


if n%27 == 0:
  print(xmax)
elif xmin == xmax:
  print(":(")
else:
  print(xmax)
n = int(input())
for i in range(1,5000):
  if int(i*1.08)==n:
    print(i)
    exit()
else:
  print(":(")
n = int(input())

for i in range(0,n):
  if(int(i*1.08) == n):
    print(i)
    exit()
  else:
    continue
print(":(")
n=int(input())
if n == 1:
    print(1)
    exit()
for i in range(n):
    if (i *108)//100 ==  n:
        print(i)
        exit()
print(':(')
N = int(input())

for i in range(1, 50001):
    if int(1.08 * i) == N:
        print(i)
        break
else:
    print(":)")
import math
N=int(input())
a=math.ceil(N/(1.08))
b=math.floor((N+1)/(1.08))
if (a>b) or (a==b and (N+1)//(1.08)==0) :
    print(':(')
else:
    print(a)
N = int(input())

for i in range(0,50001):
    if int(i*1.08)==N:
      print(N)
      exit()
print(":(")
import math

N = int(input())
ans = -1
for i in range(N):
	if math.floor(i*1.08) == N:
		ans = i
if ans == -1:
	print(':(')
else:
	print(ans)
def main():
    n = int(input())

    for i in range(1,50000):
        if round(i * 1.08) == n:
            print(i)
            exit()

    print(':(')

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

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

x = n *100//108
price= math.ceil(x)

if math.floor(price*1.08) == n:
    print(price)
else:
    print(':(')
import sys
input = sys.stdin.readline

N = int(input())

p=N/1.08
if(p==0):
	print(int(p))
else:
	if((int(p)+1*1.08)!=N):
		print(":(")
	else:
		print(int(p)+1)
n=int(input())
a=int(n/1.08)
b=int(a*1.08)
print(a, b, n)
if n==b:
  print(a)
else:
  print(":(")
N = int(input())
 
for X in range(N-1):
  if N+1 > X * 1.08 > N:
    print(X)
    break
  elif X * 1.08 > N+1:
    break
print(':(')
X = int(input())
import math
ans = math.floor(round(X/1.08))


if math.floor(round(X/1.08)*1.08) != X:
  print(":(")
else:
  print(ans)
n = int(input())
rate = 1.08
api  = round(n / rate)
api2 = round(n / rate)
if n == int(api * rate):
    print(api)
elif n == int(api2 * rate):
    print(api2)
else:
    print(":(")
N = int(input())
if N * 25 / 27 % 1 == 0:
  print(int(N * 25 / 27))
elif N * 25 / 27 % 1 >= 0.5:
  print(int(N * 25 / 27) + 1)
else:
  print(":(")
N = int(input())

if N%1.08 != 0:
  print(":(")
else:
  print(N//1.08)
n = int(input())
for i in range(n):
    if i * 1.08 // 1 == n:
        print(i)
        exit()
print(":(")
import math
n=int(input())
if (n/1.08).is_integer:
    print(int(n/1.08))
else:
    print(":(")
N = int(input())
 
ans = ":("
 
for X in range(N-1):
  if int(X * 1.08) == N:
    ans = X
    break
    
print(ans)
from math import floor

N = int(input())

Tax = False

for i in range(N):
    if floor(i*1.08) == N:
        Tax = True
        break

if Tax:
    print(i)
else:
    print(':(')
n = int(input())
f = 0
for i in range(n):
  if int(i*1.08) == n:
    print(i)
    f = 1
    break
if f == 0:
  print(':(')
import math
N = int(input())

f = int(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(f)
N = int(input())
for i in range(N):
    if int(i * 1.08) == N:
        print(i)
        exit()
print(':(')
import math
N = int(input())

ans =0

for i in range(N):
   if int(i*1.08) == N:
      print(i)
      ans += 1
      
    
    
if ans == 0:
  print(':(')
n=int(input())
ans=':('
for i in range(1,n):
  if int((i*1.08)//1)==n:
    ans=i
    break
print(ans)
import numpy

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

if numpy.floor(X1) - numpy.floor(X0) == 0:
    print(':(')
else:
    print(int(numpy.floor(X0) + 1))
n = int(input())

for i in range(n):
	if int(i * 1.08) == n:
		print(int(i))
		exit()
	else:
		print(":(")
import math

n = int(input())
plice = math.floor(n / 1.08)

for i in range(1, plice + 1):
  if math.floor(i * 1.08) == n:
    print(i)
    exit()

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())
for i in range(n):
    if int(i*1.08) == n:
        print(i)
        sys.exit()
print(":(")
import math
n = int(input())
a = math.floor(n / 1.08)
b = math.ceil(n / 1.08)
ans = ''
if a * 1.08 == n:
  ans = a
elif b * 1.08 == n:
  ans = b
else:
  ans = ':('
print(ans)
N=int(input())

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

if all(int(i*1.08)!=N for i in range(N))==True:
    print(":(")
import math
n=int(input())
x=n/1.08
xc=math.ceil(x)
nn=x*1.08
if math.floor(nn)==n:    
	print(xc)
else:
  print(":(")
N = float(input())
raw = N / 1.08
check = round(raw) * 1.08
if (check - N) >= 0:
  print(round(raw))
else :
  print(":(")
import math
n = int(input())
a = math.floor(n / 1.08)
b = math.ceil(n / 1.08)
ans = ''
if a * 1.08 == n:
  ans = a
else:
  ans = ':('
print(ans)
N = int(input())
x = N//1.08

if N % 1.08 == 0:
    print(int(x))
else:
    if (x+1) * 1.08 >=  N:
        print(int(x+1))
    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(":(")
import math

n = int(input())
o = n / 1.08

o_int = math.floor(o)

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

else:
    print(":(")
s=int(input())
n = int(s/1.08)

for i in range(n):
    if int(n*1.08)==s:
        print(n)
        break
    elif int(n*1.08)<s:
        n+=1
        continue
    else:
        print(":(")
        break
from decimal import Decimal
N = int(input())
M = N/Decimal(1.08)
if N == int(M*Decimal(1.08)) :
    print( int(M))
else :
    print(':(')
import sys
n=int(input())
for i in range(n):
    if (i*1.08==n):
        print (i)
        sys.exit() 
print(":(")
n = int(input())
rate = 1.08
api  = round(n / rate)
api2 = int(n / rate)
if n == int(api * rate):
    print(api)
elif n == int(api2 * rate):
    print(api2)
else:
    print(":(")
import math
N=float(input())
a=math.ceil(N/(1.08))
for i in range(a,int(N)):
    if math.floor(i*1.08)==N:
        print(a)
        break
    else:
        print(':(')
import math

N = int(input())

of = math.floor(N / 108 * 100)
oc = math.ceil(N / 108 * 100)
o = round(N / 108 * 100)

if(int(of * 108 / 100) != N and int(oc * 108 / 100) != N):
    print(":(")
else:
    print(o)
n=int(input())
for i in range(50000):
    if i*1.08==n:
        print(i)
        exit()
print(":(")
N = int(input())

ans = 0
for i in range(N - int(N/20), N + int(N/20)):
    if int(i*1.08) == N:
        ans = i
        break

if ans != 0:
    print(ans)
else:
    print(":(")
pay=int(input())
price=int(pay/1.08)
#print(price)
if int(price*1.08)==pay or int((price+1)*1.08)==pay:
    print(price)
else:
    print(':(')
N = int(input())

est_X = int(N/1.08)*1.08

if int(est_X) == N:
    print(est_X)
elif int(est_X + 1) == N:
    print(est_X + 1)
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(":(")
a = int(input())
if a/1.08 == int(a/1.08):
    print(int(a/1.08))
else:
    print(':(')
def resolve():
    import math
    N = int(input())
    n = math.floor(N*0.9)
    for i in range(n, N):
        if math.floor(i*1.08) == N:
            print(i)
            exit()
    print(":(")
resolve()
import math
s=int(input())
n = math.floor(s/1.08)

for i in range(n):
    if math.floor(n*1.08)==s:
        print(n)
        break
    elif math.floor(n*1.08)<s:
        n+=1
        continue
    else:
        print(":(")
        break
N = int(input())*100
x = N // 108
M = (x * 108) // 1
if N == M:
  print(x)
else:
  print(':(')
n=int(input())
for i in range(n):
  if i*1.08>=n and i*1.08<n+1:
    print(i)
    break
else:
  print(":(")
n=int(input())
x=int(n/1.08)
if(round(1.08*x*10)==n*10):
    print(x)
else:
    print(":(")
n = int(input())

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

est_X = int(int(N/1.08)*1.08)

if est_X == N:
    print(est_X)
elif est_X + 1 == N:
    print(est_X + 1)
else:
    print(':(')
import math
def resolve():
    N = int(input())
    if (N + 1) * 100 % 108 == 0:
        print(":(")
    else:
        print(math.ceil(N/1.08))
resolve()
n=int(input())
a=n//1.08
b=int(a*1.08)
if n==b:
  print(a)
else:
  print(":(")
import math
n=int(input())
if int(math.ceil(n/1.08)*1.08)==n:
    print(math.ceil(n/1.08))
else:
    print(":()")
N = int(input())
 
ans = ":("
for X in range(1, N):
  if X * 1.08 >= N:
    ans = X
    break
  elif X * 1.08 > N+1:
    break
    
print(ans)
n = int(input())
for i in range(int(n * (25 / 27)), int(n * (25/ 27) + 3)):
    if int(i * 1.08) == n:
        print(i)
        exit()
print(-1)
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(':/')