
# 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()))

L = [ 0 ] * 1000000



L[0] = 2

L[1] = 1



for i in range(2, N+1):

  L[i] = L[i-2] + L[i-1]



print((L[N]))


# optimized version of the same code:

N = int(eval(input()))

L = [ 0 ] * (N+1)



L[0] = 2

L[1] = 1



for i in range(2, N+1):

  L[i] = L[i-2] + L[i-1]



print((L[N]))

N = int(eval(input()))
L = [0] * 1000000
L[0] = 2
L[1] = 1
for i in range(2, N + 1):
    L[i] = L[i - 2] + L[i - 1]
print((L[N]))

N = int(eval(input()))
L = [0] * (N + 1)
L[0] = 2
L[1] = 1
for i in range(2, N + 1):
    L[i] = L[i - 2] + L[i - 1]
print((L[N]))

-L = [0] * 1000000 +L = [0] * (N + 1)