
# slower version:

s = input()
for i in range(len(s)):
  if i%2 == 0:
    print(s[i], end = '')


# optimized version of the same code:

s = input()
ans = ''
for i in range(len(s)):
  if i % 2 == 0:
    ans += s[i]
print(ans)



# slower version:

import sys

input = sys.stdin.readline

sys.setrecursionlimit(10**7)

INF = 10**10

MOD = 10**9 + 7

X = int(eval(input()))

for i in range(1000):

    for j in range(-1000,1000):

        #print (i**5 - j**5)

        if i**5 - j**5 == X:

            print((i,j))

            exit()

   

# optimized version of the same code:

import sys

input = sys.stdin.readline

sys.setrecursionlimit(10**7)

INF = 10**10

MOD = 10**9 + 7

X = int(eval(input()))

MAX_X = 10**9

n = 0

while(1):

    n+=1

    if n**5 - (n-1)**5 > MAX_X:

        break

for i in range(n):

    for j in range(-n+1,n-1):

        if i**5 - j**5 == X:

            print((i,j))

            exit()

   
import sys

input = sys.stdin.readline
sys.setrecursionlimit(10**7)
INF = 10**10
MOD = 10**9 + 7
X = int(eval(input()))
for i in range(1000):
    for j in range(-1000, 1000):
        # print (i**5 - j**5)
        if i**5 - j**5 == X:
            print((i, j))
            exit()

import sys

input = sys.stdin.readline
sys.setrecursionlimit(10**7)
INF = 10**10
MOD = 10**9 + 7
X = int(eval(input()))
MAX_X = 10**9
n = 0
while 1:
    n += 1
    if n**5 - (n - 1) ** 5 > MAX_X:
        break
for i in range(n):
    for j in range(-n + 1, n - 1):
        if i**5 - j**5 == X:
            print((i, j))
            exit()

-for i in range(1000): -    for j in range(-1000, 1000): -        # print (i**5 - j**5) +MAX_X = 10**9 +n = 0 +while 1: +    n += 1 +    if n**5 - (n - 1) ** 5 > MAX_X: +        break +for i in range(n): +    for j in range(-n + 1, n - 1):