
# 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(input())

a = list(map(int, input().split()))



tmp = [[e, n - i] for i, e in enumerate(a)]

tmp.sort(reverse=True)



aa = [[e, n - i] for e, i in tmp] + [[0, -1]]



v_prev, i_prev = aa[0]

i = 0

ans = [0] * n

sm = 0

while i < n:

    while aa[i][1] >= i_prev:

        sm += aa[i][0]

        i += 1



    ans[i_prev] += sm - aa[i][0] * i

    sm = aa[i][0] * i

    v_prev, i_prev = aa[i]



print(*ans, sep="\n")


# optimized version of the same code:

from bisect import bisect_right



n = int(input())

a = list(map(int, input().split()))



li = [[0, -1]]

for i, e in enumerate(a):

    if e > li[-1][0]:

        li.append([e, i])



li = li[::-1]



a.sort()

acc = [0] * (n + 1)

for i in range(n - 1, -1, -1):

    acc[i] = acc[i+1] + a[i]



ans = [0] * n

sub = 0

ans_prev = 0

for (ep, ip), (e, i) in zip(li, li[1:]):

    j = bisect_right(a, e)

    ans[ip] = acc[j] - e * (n - j)



i_prev = 0

for i in range(1, n):

    if ans[i]:

        ans[i_prev] -= ans[i]

        i_prev = i



print(*ans, sep="\n")

n = int(input())
a = list(map(int, input().split()))
tmp = [[e, n - i] for i, e in enumerate(a)]
tmp.sort(reverse=True)
aa = [[e, n - i] for e, i in tmp] + [[0, -1]]
v_prev, i_prev = aa[0]
i = 0
ans = [0] * n
sm = 0
while i < n:
    while aa[i][1] >= i_prev:
        sm += aa[i][0]
        i += 1
    ans[i_prev] += sm - aa[i][0] * i
    sm = aa[i][0] * i
    v_prev, i_prev = aa[i]
print(*ans, sep="\n")

from bisect import bisect_right

n = int(input())
a = list(map(int, input().split()))
li = [[0, -1]]
for i, e in enumerate(a):
    if e > li[-1][0]:
        li.append([e, i])
li = li[::-1]
a.sort()
acc = [0] * (n + 1)
for i in range(n - 1, -1, -1):
    acc[i] = acc[i + 1] + a[i]
ans = [0] * n
sub = 0
ans_prev = 0
for (ep, ip), (e, i) in zip(li, li[1:]):
    j = bisect_right(a, e)
    ans[ip] = acc[j] - e * (n - j)
i_prev = 0
for i in range(1, n):
    if ans[i]:
        ans[i_prev] -= ans[i]
        i_prev = i
print(*ans, sep="\n")

+from bisect import bisect_right + -tmp = [[e, n - i] for i, e in enumerate(a)] -tmp.sort(reverse=True) -aa = [[e, n - i] for e, i in tmp] + [[0, -1]] -v_prev, i_prev = aa[0] -i = 0 +li = [[0, -1]] +for i, e in enumerate(a): +    if e > li[-1][0]: +        li.append([e, i]) +li = li[::-1] +a.sort() +acc = [0] * (n + 1) +for i in range(n - 1, -1, -1): +    acc[i] = acc[i + 1] + a[i] -sm = 0 -while i < n: -    while aa[i][1] >= i_prev: -        sm += aa[i][0] -        i += 1 -    ans[i_prev] += sm - aa[i][0] * i -    sm = aa[i][0] * i -    v_prev, i_prev = aa[i] +sub = 0 +ans_prev = 0 +for (ep, ip), (e, i) in zip(li, li[1:]): +    j = bisect_right(a, e) +    ans[ip] = acc[j] - e * (n - j) +i_prev = 0 +for i in range(1, n): +    if ans[i]: +        ans[i_prev] -= ans[i] +        i_prev = i