sl=list(input())



n=len(sl)

li=[]

for i in range(1,n+1) :

  if i % 2 != 0 :

    li.append(sl[i-1])

print(*li,sep="")

#n = int(input())

#a, b = map(int,input().split())

#l = list(map(int,input().split()))

#l = [list(map(int,input().split())) for i in range(n)]

s = list(eval(input()))

ans = ''

for i, si in enumerate(s):

    if (i+1) % 2 != 0:

        ans += si

print(ans)

sl = list(input())
n = len(sl)
li = []
for i in range(1, n + 1):
    if i % 2 != 0:
        li.append(sl[i - 1])
print(*li, sep="")

# n = int(input())
# a, b = map(int,input().split())
# l = list(map(int,input().split()))
# l = [list(map(int,input().split())) for i in range(n)]
s = list(eval(input()))
ans = ""
for i, si in enumerate(s):
    if (i + 1) % 2 != 0:
        ans += si
print(ans)

-sl = list(input()) -n = len(sl) -li = [] -for i in range(1, n + 1): -    if i % 2 != 0: -        li.append(sl[i - 1]) -print(*li, sep="") +# n = int(input()) +# a, b = map(int,input().split()) +# l = list(map(int,input().split())) +# l = [list(map(int,input().split())) for i in range(n)] +s = list(eval(input())) +ans = "" +for i, si in enumerate(s): +    if (i + 1) % 2 != 0: +        ans += si +print(ans)