
# 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 time

t=time.time()

A,B,C=list(map(int,input().split()))

cnt=0

while(A%2==B%2==C%2==0):

    a,b,c=A,B,C

    A=b//2+c//2;B=a//2+c//2;C=a//2+b//2

    cnt+=1

    if(time.time()-t>=1):

        print((-1))

        exit()

print(cnt)

# optimized version of the same code:

A,B,C=list(map(int,input().split()))

cnt=0

if(A==B==C):

    if A%2!=0:

        print((0))

    else:

        print((-1))

    exit()

while(A%2==B%2==C%2==0):

    a,b,c=A,B,C

    A=b//2+c//2;B=a//2+c//2;C=a//2+b//2

    cnt+=1

print(cnt)
import time

t = time.time()
A, B, C = list(map(int, input().split()))
cnt = 0
while A % 2 == B % 2 == C % 2 == 0:
    a, b, c = A, B, C
    A = b // 2 + c // 2
    B = a // 2 + c // 2
    C = a // 2 + b // 2
    cnt += 1
    if time.time() - t >= 1:
        print((-1))
        exit()
print(cnt)

A, B, C = list(map(int, input().split()))
cnt = 0
if A == B == C:
    if A % 2 != 0:
        print((0))
    else:
        print((-1))
    exit()
while A % 2 == B % 2 == C % 2 == 0:
    a, b, c = A, B, C
    A = b // 2 + c // 2
    B = a // 2 + c // 2
    C = a // 2 + b // 2
    cnt += 1
print(cnt)

-import time - -t = time.time() +if A == B == C: +    if A % 2 != 0: +        print((0)) +    else: +        print((-1)) +    exit() -    if time.time() - t >= 1: -        print((-1)) -        exit()