
# 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 numpy as np



S=eval(input())

S=np.array([1 if s=='B' else 0 for s in S])



print((np.abs(np.diff(S)).sum()))


# optimized version of the same code:

from itertools import groupby



S=eval(input())

answer = sum([1 for _ in groupby(S)]) -1



print(answer)
import numpy as np

S = eval(input())
S = np.array([1 if s == "B" else 0 for s in S])
print((np.abs(np.diff(S)).sum()))

from itertools import groupby

S = eval(input())
answer = sum([1 for _ in groupby(S)]) - 1
print(answer)

-import numpy as np +from itertools import groupby -S = np.array([1 if s == "B" else 0 for s in S]) -print((np.abs(np.diff(S)).sum())) +answer = sum([1 for _ in groupby(S)]) - 1 +print(answer)