
# 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 re;print((max(list(map(len,re.split('[^ACGT]',eval(input())))))))

# optimized version of the same code:

p=m=0

for c in eval(input()):p=-~p*(c in'ATGC');m=max(m,p)

print(m)
import re

print((max(list(map(len, re.split("[^ACGT]", eval(input())))))))

p = m = 0
for c in eval(input()):
    p = -~p * (c in "ATGC")
    m = max(m, p)
print(m)

-import re - -print((max(list(map(len, re.split("[^ACGT]", eval(input()))))))) +p = m = 0 +for c in eval(input()): +    p = -~p * (c in "ATGC") +    m = max(m, p) +print(m)