
# 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:

n = int(eval(input()))

s = []

for i in range(1, 10):

  for j in range(1, 10):

    s.append(i*j)

if n in s:

  print("Yes")

else:

  print("No")

# optimized version of the same code:

import sys



n = int(eval(input()))

for i in range(1, 10):

  for j in range(1, 10):

    if i*j == n:

      print("Yes")

      sys.exit()

print("No")

n = int(eval(input()))
s = []
for i in range(1, 10):
    for j in range(1, 10):
        s.append(i * j)
if n in s:
    print("Yes")
else:
    print("No")

import sys

n = int(eval(input()))
for i in range(1, 10):
    for j in range(1, 10):
        if i * j == n:
            print("Yes")
            sys.exit()
print("No")

+import sys + -s = [] -        s.append(i * j) -if n in s: -    print("Yes") -else: -    print("No") +        if i * j == n: +            print("Yes") +            sys.exit() +print("No")