
# 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:

a=65280; b=61680; c=52428; d=43690; e=65535

from heapq import heappush, heappop

base = [a, b, c, d, e, 0]

Q = [(1, el) for el in base]

L = {el: 1 for el in base}

H = []

get = L.get

push = H.append

while Q:

    l, p = heappop(Q)

    if L[p] < l: continue

    if l+1 < get(p ^ e, 17):

        L[p ^ e] = l+1

        if l+1 < 16: heappush(Q, (l+1, p ^ e))

    if l+3 < 16:

        for q, r in H:

            if l+r+3 <= 16:

                if l+r+3 < get(p & q, 17):

                    L[p & q] = l+r+3

                    if l+r+3 < 16: heappush(Q, (l+r+3, p & q))

                if l+r+3 < get(p ^ q, 17):

                    L[p ^ q] = l+r+3

                    if l+r+3 < 16: heappush(Q, (l+r+3, p ^ q))

            else: break

    if l < 7: push((p, l))

print(*map(L.__getitem__, eval("e&%s"%",e&".join(open(0).read().replace(*"-~").replace(*"*&").replace(*"1e").split()[:-1]))),sep='\n')


# optimized version of the same code:

a=65280; b=61680; c=52428; d=43690; e=65535

from heapq import heappush, heappop

Q = [(1, a), (1, b), (1, c), (1, d)]

L = {a: 1, b: 1, c: 1, d: 1, e: 1, e: 1, 0: 1}

H = []

get = L.get

push = H.append

while Q:

    l, p = heappop(Q)

    if L[p] < l: continue

    if l+1 < get(p ^ e, 17):

        L[p ^ e] = l+1

        l < 15 and heappush(Q, (l+1, p ^ e))

    if l < 13:

        li = 13-l; l3 = 3+l

        for q, r in H:

            if r <= li:

                k = p & q

                if r < get(k, 17)-l3:

                    L[k] = l3+r

                    r < li and heappush(Q, (l3+r, k))

                k = p ^ q

                if r < get(k, 17)-l3:

                    L[k] = l3+r

                    r < li and heappush(Q, (l3+r, k))

            else: break

    if l < 7: push((p, l))

print(*map(L.__getitem__, eval("e&"+",e&".join(open(0).read().replace(*"-~").replace(*"*&").replace(*"1e").split()[:-1]))),sep='\n')

a = 65280
b = 61680
c = 52428
d = 43690
e = 65535
from heapq import heappush, heappop

base = [a, b, c, d, e, 0]
Q = [(1, el) for el in base]
L = {el: 1 for el in base}
H = []
get = L.get
push = H.append
while Q:
    l, p = heappop(Q)
    if L[p] < l:
        continue
    if l + 1 < get(p ^ e, 17):
        L[p ^ e] = l + 1
        if l + 1 < 16:
            heappush(Q, (l + 1, p ^ e))
    if l + 3 < 16:
        for q, r in H:
            if l + r + 3 <= 16:
                if l + r + 3 < get(p & q, 17):
                    L[p & q] = l + r + 3
                    if l + r + 3 < 16:
                        heappush(Q, (l + r + 3, p & q))
                if l + r + 3 < get(p ^ q, 17):
                    L[p ^ q] = l + r + 3
                    if l + r + 3 < 16:
                        heappush(Q, (l + r + 3, p ^ q))
            else:
                break
    if l < 7:
        push((p, l))
print(
    *map(
        L.__getitem__,
        eval(
            "e&%s"
            % ",e&".join(
                open(0).read().replace(*"-~").replace(*"*&").replace(*"1e").split()[:-1]
            )
        ),
    ),
    sep="\n"
)

a = 65280
b = 61680
c = 52428
d = 43690
e = 65535
from heapq import heappush, heappop

Q = [(1, a), (1, b), (1, c), (1, d)]
L = {a: 1, b: 1, c: 1, d: 1, e: 1, e: 1, 0: 1}
H = []
get = L.get
push = H.append
while Q:
    l, p = heappop(Q)
    if L[p] < l:
        continue
    if l + 1 < get(p ^ e, 17):
        L[p ^ e] = l + 1
        l < 15 and heappush(Q, (l + 1, p ^ e))
    if l < 13:
        li = 13 - l
        l3 = 3 + l
        for q, r in H:
            if r <= li:
                k = p & q
                if r < get(k, 17) - l3:
                    L[k] = l3 + r
                    r < li and heappush(Q, (l3 + r, k))
                k = p ^ q
                if r < get(k, 17) - l3:
                    L[k] = l3 + r
                    r < li and heappush(Q, (l3 + r, k))
            else:
                break
    if l < 7:
        push((p, l))
print(
    *map(
        L.__getitem__,
        eval(
            "e&"
            + ",e&".join(
                open(0).read().replace(*"-~").replace(*"*&").replace(*"1e").split()[:-1]
            )
        ),
    ),
    sep="\n"
)

-base = [a, b, c, d, e, 0] -Q = [(1, el) for el in base] -L = {el: 1 for el in base} +Q = [(1, a), (1, b), (1, c), (1, d)] +L = {a: 1, b: 1, c: 1, d: 1, e: 1, e: 1, 0: 1} -        if l + 1 < 16: -            heappush(Q, (l + 1, p ^ e)) -    if l + 3 < 16: +        l < 15 and heappush(Q, (l + 1, p ^ e)) +    if l < 13: +        li = 13 - l +        l3 = 3 + l -            if l + r + 3 <= 16: -                if l + r + 3 < get(p & q, 17): -                    L[p & q] = l + r + 3 -                    if l + r + 3 < 16: -                        heappush(Q, (l + r + 3, p & q)) -                if l + r + 3 < get(p ^ q, 17): -                    L[p ^ q] = l + r + 3 -                    if l + r + 3 < 16: -                        heappush(Q, (l + r + 3, p ^ q)) +            if r <= li: +                k = p & q +                if r < get(k, 17) - l3: +                    L[k] = l3 + r +                    r < li and heappush(Q, (l3 + r, k)) +                k = p ^ q +                if r < get(k, 17) - l3: +                    L[k] = l3 + r +                    r < li and heappush(Q, (l3 + r, k)) -            "e&%s" -            % ",e&".join( +            "e&" +            + ",e&".join(