
# 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 decimal import *

getcontext().prec = 14



N, D = list(map(int, input().split()))





def distance(x1, x2, y1, y2):

    dx = x2-x1

    dy = y2-y1

    return (dx*dx + dy*dy).sqrt()





X = [0] * N

Y = [0] * N

ans = 0

for i in range(N):

    X[i], Y[i] = list(map(Decimal, input().split()))

    if (distance(0, X[i], 0, Y[i]) <= D):

        ans += 1



print(ans)


# optimized version of the same code:

from decimal import *

getcontext().prec = 14  # あんまり大きいと計算遅いかも



N, D = list(map(int, input().split()))



def distance(x1, x2, y1, y2):

    dx = x2-x1

    dy = y2-y1

    return (dx*dx + dy*dy).sqrt()



ans = 0

for i in range(N):

    X, Y = list(map(Decimal, input().split()))

    if (distance(0, X, 0, Y) <= D):

        ans += 1



print(ans)

from decimal import *

getcontext().prec = 14
N, D = list(map(int, input().split()))


def distance(x1, x2, y1, y2):
    dx = x2 - x1
    dy = y2 - y1
    return (dx * dx + dy * dy).sqrt()


X = [0] * N
Y = [0] * N
ans = 0
for i in range(N):
    X[i], Y[i] = list(map(Decimal, input().split()))
    if distance(0, X[i], 0, Y[i]) <= D:
        ans += 1
print(ans)

from decimal import *

getcontext().prec = 14  # あんまり大きいと計算遅いかも
N, D = list(map(int, input().split()))


def distance(x1, x2, y1, y2):
    dx = x2 - x1
    dy = y2 - y1
    return (dx * dx + dy * dy).sqrt()


ans = 0
for i in range(N):
    X, Y = list(map(Decimal, input().split()))
    if distance(0, X, 0, Y) <= D:
        ans += 1
print(ans)

-getcontext().prec = 14 +getcontext().prec = 14  # あんまり大きいと計算遅いかも -X = [0] * N -Y = [0] * N -    X[i], Y[i] = list(map(Decimal, input().split())) -    if distance(0, X[i], 0, Y[i]) <= D: +    X, Y = list(map(Decimal, input().split())) +    if distance(0, X, 0, Y) <= D: