
# 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 collections

n = int(eval(input()))

a=[eval(input()) for _ in range(n)]

anslist=[]

b=collections.Counter(a)

c=max(list(b.values()))

for i in b:

    if b[i]==c:

        anslist.append(i)

d=sorted(anslist)

for i in tuple(d):

    print(i)

# optimized version of the same code:

from collections import Counter

n=int(eval(input()))

a=[]

for i in range(n):

  a.append(eval(input()))

ac=Counter(a)

acs=sorted(list(ac.items()),key=lambda x:x[1],reverse=1)

z=len(acs)

i=0

temp=[]



while i<=z-1 and acs[i][1]==acs[0][1] :

  temp.append(acs[i][0])

  i+=1

temp.sort()

for i in temp:

  print(i)
import collections

n = int(eval(input()))
a = [eval(input()) for _ in range(n)]
anslist = []
b = collections.Counter(a)
c = max(list(b.values()))
for i in b:
    if b[i] == c:
        anslist.append(i)
d = sorted(anslist)
for i in tuple(d):
    print(i)

from collections import Counter

n = int(eval(input()))
a = []
for i in range(n):
    a.append(eval(input()))
ac = Counter(a)
acs = sorted(list(ac.items()), key=lambda x: x[1], reverse=1)
z = len(acs)
i = 0
temp = []
while i <= z - 1 and acs[i][1] == acs[0][1]:
    temp.append(acs[i][0])
    i += 1
temp.sort()
for i in temp:
    print(i)

-import collections +from collections import Counter -a = [eval(input()) for _ in range(n)] -anslist = [] -b = collections.Counter(a) -c = max(list(b.values())) -for i in b: -    if b[i] == c: -        anslist.append(i) -d = sorted(anslist) -for i in tuple(d): +a = [] +for i in range(n): +    a.append(eval(input())) +ac = Counter(a) +acs = sorted(list(ac.items()), key=lambda x: x[1], reverse=1) +z = len(acs) +i = 0 +temp = [] +while i <= z - 1 and acs[i][1] == acs[0][1]: +    temp.append(acs[i][0]) +    i += 1 +temp.sort() +for i in temp: