
# 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()))

v = [[tuple(map(int, input().split()))for i in range(int(eval(input())))]

     for i in range(n)]



ans = 0

for i in range(2**n):

    f = [False] * n

    xy = []

    for j in range(n):

        if (i >> j) & 1:

            f[j] = True

            xy.append(v[j])

    flag = True

    for xyi in xy:

        for x, y in xyi:

            if f[x - 1] is not bool(y):

                flag = False

                break

    if flag:

        ans = max(ans, len(xy))

print(ans)


# optimized version of the same code:

n = int(eval(input()))

v = [[tuple(map(int, input().split()))for i in range(int(eval(input())))]

     for i in range(n)]



ans = 0

for i in range(2**n):

    f = [0] * n

    xy = []

    for j in range(n):

        if (i >> j) & 1:

            f[j] = 1

            xy.append(v[j])

    flag = True

    for xyi in xy:

        for x, y in xyi:

            #print(f,x,y,bin(i))

            if (i>>(x-1))&1 != y:

                flag = False

                break

    if flag:

        ans = max(ans, len(xy))

print(ans)

n = int(eval(input()))
v = [
    [tuple(map(int, input().split())) for i in range(int(eval(input())))]
    for i in range(n)
]
ans = 0
for i in range(2**n):
    f = [False] * n
    xy = []
    for j in range(n):
        if (i >> j) & 1:
            f[j] = True
            xy.append(v[j])
    flag = True
    for xyi in xy:
        for x, y in xyi:
            if f[x - 1] is not bool(y):
                flag = False
                break
    if flag:
        ans = max(ans, len(xy))
print(ans)

n = int(eval(input()))
v = [
    [tuple(map(int, input().split())) for i in range(int(eval(input())))]
    for i in range(n)
]
ans = 0
for i in range(2**n):
    f = [0] * n
    xy = []
    for j in range(n):
        if (i >> j) & 1:
            f[j] = 1
            xy.append(v[j])
    flag = True
    for xyi in xy:
        for x, y in xyi:
            # print(f,x,y,bin(i))
            if (i >> (x - 1)) & 1 != y:
                flag = False
                break
    if flag:
        ans = max(ans, len(xy))
print(ans)

-    f = [False] * n +    f = [0] * n -            f[j] = True +            f[j] = 1 -            if f[x - 1] is not bool(y): +            # print(f,x,y,bin(i)) +            if (i >> (x - 1)) & 1 != y: