
# 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:

from numpy import*

a,b=median(t:=loadtxt(open(0),skiprows=1),0)

print((int((a-b)*~(~len(t)%2))+1))

# optimized version of the same code:

from statistics import*

(n,),*t=[list(map(int,t.split()))for t in open(0)]

a,b=list(map(median,list(zip(*t))))

print((int((b-a)*(2-n%2))+1))
from numpy import *

a, b = median(t := loadtxt(open(0), skiprows=1), 0)
print((int((a - b) * ~(~len(t) % 2)) + 1))

from statistics import *

(n,), *t = [list(map(int, t.split())) for t in open(0)]
a, b = list(map(median, list(zip(*t))))
print((int((b - a) * (2 - n % 2)) + 1))

-from numpy import * +from statistics import * -a, b = median(t := loadtxt(open(0), skiprows=1), 0) -print((int((a - b) * ~(~len(t) % 2)) + 1)) +(n,), *t = [list(map(int, t.split())) for t in open(0)] +a, b = list(map(median, list(zip(*t)))) +print((int((b - a) * (2 - n % 2)) + 1))