
# 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 numpy as np

# Me





def f():

    i = int(eval(input()))

    nums = np.array(list(map(int, input().split())))

    # nums = [int(x) for x in input().split()]

    c = 0

    while True:

        if any(nums % 2 == 1):

            break

        c += 1

        nums = nums / 2

    print(c)





f()





# Other


# optimized version of the same code:

def divide_all(a):

    success = True

    for i, n in enumerate(a):

        if n % 2 != 0:

            success = False

            break

        a[i] = n / 2

    if success is False:

        return (a, False)

    return (a, True)



n = int(eval(input()))

a = list(map(int, input().split()))

c = 0

while True:

    a, r = divide_all(a)

    if r is False:

        break

    c += 1





print(c)

import numpy as np

# Me
def f():
    i = int(eval(input()))
    nums = np.array(list(map(int, input().split())))
    # nums = [int(x) for x in input().split()]
    c = 0
    while True:
        if any(nums % 2 == 1):
            break
        c += 1
        nums = nums / 2
    print(c)


f()
# Other

def divide_all(a):
    success = True
    for i, n in enumerate(a):
        if n % 2 != 0:
            success = False
            break
        a[i] = n / 2
    if success is False:
        return (a, False)
    return (a, True)


n = int(eval(input()))
a = list(map(int, input().split()))
c = 0
while True:
    a, r = divide_all(a)
    if r is False:
        break
    c += 1
print(c)

-import numpy as np - -# Me -def f(): -    i = int(eval(input())) -    nums = np.array(list(map(int, input().split()))) -    # nums = [int(x) for x in input().split()] -    c = 0 -    while True: -        if any(nums % 2 == 1): +def divide_all(a): +    success = True +    for i, n in enumerate(a): +        if n % 2 != 0: +            success = False -        c += 1 -        nums = nums / 2 -    print(c) +        a[i] = n / 2 +    if success is False: +        return (a, False) +    return (a, True) -f() -# Other +n = int(eval(input())) +a = list(map(int, input().split())) +c = 0 +while True: +    a, r = divide_all(a) +    if r is False: +        break +    c += 1 +print(c)