
# 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:

def main():

    from sys import stdin

    def input():

        return stdin.readline().strip()



    n, m = list(map(int, input().split()))

    tree = [[] for _ in range(n)]

    for _ in range(m):

        i, j, k = list(map(int, input().split()))

        i -= 1

        j -= 1

        tree[i].append((k, j))

        tree[j].append((k, i))



    # dijkstra

    import heapq

    from numpy import zeros



    ans = 0

    for i in range(n):

        for j in tree[i]:

            seen = zeros(n)

            goal = j[1]

            base = j[0]

            seen[i] = 1

            todo = []

            heapq.heapify(todo)

            for k in tree[i]:

                if k[0] < base and k != j:

                    heapq.heappush(todo, k)

            while len(todo) > 0:

                k = heapq.heappop(todo)

                if k[1] == goal:

                    if k[0] < base:

                        ans += 1

                    break

                seen[k[1]] = 1

                for l in tree[k[1]]:

                    if seen[l[1]] == 0 and k[0] + l[0] < base:

                        heapq.heappush(todo, (k[0] + l[0], l[1]))



    print((ans // 2))



main()

# optimized version of the same code:

def main():

    from sys import stdin

    def input():

        return stdin.readline().strip()



    n, m = list(map(int, input().split()))

    tree = [[] for _ in range(n)]

    for _ in range(m):

        i, j, k = list(map(int, input().split()))

        i -= 1

        j -= 1

        tree[i].append((k, j))

        tree[j].append((k, i))



    # dijkstra

    import heapq



    ans = 0

    for i in range(n):

        for j in tree[i]:

            seen = [0] * n

            goal = j[1]

            base = j[0]

            seen[i] = 1

            todo = []

            heapq.heapify(todo)

            for k in tree[i]:

                if k[0] < base and k != j:

                    heapq.heappush(todo, k)

            while len(todo) > 0:

                k = heapq.heappop(todo)

                if k[1] == goal:

                    if k[0] < base:

                        ans += 1

                    break

                seen[k[1]] = 1

                for l in tree[k[1]]:

                    if seen[l[1]] == 0 and k[0] + l[0] < base:

                        heapq.heappush(todo, (k[0] + l[0], l[1]))



    print((ans // 2))



main()
def main():
    from sys import stdin

    def input():
        return stdin.readline().strip()

    n, m = list(map(int, input().split()))
    tree = [[] for _ in range(n)]
    for _ in range(m):
        i, j, k = list(map(int, input().split()))
        i -= 1
        j -= 1
        tree[i].append((k, j))
        tree[j].append((k, i))
    # dijkstra
    import heapq
    from numpy import zeros

    ans = 0
    for i in range(n):
        for j in tree[i]:
            seen = zeros(n)
            goal = j[1]
            base = j[0]
            seen[i] = 1
            todo = []
            heapq.heapify(todo)
            for k in tree[i]:
                if k[0] < base and k != j:
                    heapq.heappush(todo, k)
            while len(todo) > 0:
                k = heapq.heappop(todo)
                if k[1] == goal:
                    if k[0] < base:
                        ans += 1
                    break
                seen[k[1]] = 1
                for l in tree[k[1]]:
                    if seen[l[1]] == 0 and k[0] + l[0] < base:
                        heapq.heappush(todo, (k[0] + l[0], l[1]))
    print((ans // 2))


main()

def main():
    from sys import stdin

    def input():
        return stdin.readline().strip()

    n, m = list(map(int, input().split()))
    tree = [[] for _ in range(n)]
    for _ in range(m):
        i, j, k = list(map(int, input().split()))
        i -= 1
        j -= 1
        tree[i].append((k, j))
        tree[j].append((k, i))
    # dijkstra
    import heapq

    ans = 0
    for i in range(n):
        for j in tree[i]:
            seen = [0] * n
            goal = j[1]
            base = j[0]
            seen[i] = 1
            todo = []
            heapq.heapify(todo)
            for k in tree[i]:
                if k[0] < base and k != j:
                    heapq.heappush(todo, k)
            while len(todo) > 0:
                k = heapq.heappop(todo)
                if k[1] == goal:
                    if k[0] < base:
                        ans += 1
                    break
                seen[k[1]] = 1
                for l in tree[k[1]]:
                    if seen[l[1]] == 0 and k[0] + l[0] < base:
                        heapq.heappush(todo, (k[0] + l[0], l[1]))
    print((ans // 2))


main()

-    from numpy import zeros -            seen = zeros(n) +            seen = [0] * n