
# 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:

import sys

import heapq





# \n

def input():

    return sys.stdin.readline().rstrip()





def main():

    X, Y, Z, K = list(map(int, input().split()))

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

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

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



    A.sort(reverse=True)

    B.sort(reverse=True)

    C.sort(reverse=True)



    Q = []

    S = set()

    heapq.heapify(Q)

    heapq.heappush(Q, (-A[0] - B[0] - C[0], 0, 0, 0))

    for i in range(K):

        m, a, b, c = heapq.heappop(Q)

        print((-m))

        if (a + 1, b, c) not in S and a + 1 < X:

            heapq.heappush(Q, (-A[a + 1] - B[b] - C[c], a + 1, b, c))

            S.add((a + 1, b, c))

        if (a, b + 1, c) not in S and b + 1 < Y:

            heapq.heappush(Q, (-A[a] - B[b + 1] - C[c], a, b + 1, c))

            S.add((a, b + 1, c))

        if (a, b, c + 1) not in S and c + 1 < Z:

            heapq.heappush(Q, (-A[a ] - B[b] - C[c+1], a, b, c + 1))

            S.add((a, b, c + 1))





if __name__ == "__main__":

    main()


# optimized version of the same code:

import sys





# \n

def input():

    return sys.stdin.readline().rstrip()





def main():

    X, Y, Z, K = list(map(int, input().split()))

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

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

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



    A.sort(reverse=True)

    B.sort(reverse=True)

    C.sort(reverse=True)



    L = []



    for i in range(X):

        for j in range(min(Y, K // (i + 1) + 1)):

            for k in range(min(Z, K // (i + 1) // (j + 1) + 1)):

                L.append(A[i] + B[j] + C[k])



    L.sort(reverse=True)



    for i in range(K):

        print((L[i]))





if __name__ == "__main__":

    main()

import sys
import heapq

# \n
def input():
    return sys.stdin.readline().rstrip()


def main():
    X, Y, Z, K = list(map(int, input().split()))
    A = list(map(int, input().split()))
    B = list(map(int, input().split()))
    C = list(map(int, input().split()))
    A.sort(reverse=True)
    B.sort(reverse=True)
    C.sort(reverse=True)
    Q = []
    S = set()
    heapq.heapify(Q)
    heapq.heappush(Q, (-A[0] - B[0] - C[0], 0, 0, 0))
    for i in range(K):
        m, a, b, c = heapq.heappop(Q)
        print((-m))
        if (a + 1, b, c) not in S and a + 1 < X:
            heapq.heappush(Q, (-A[a + 1] - B[b] - C[c], a + 1, b, c))
            S.add((a + 1, b, c))
        if (a, b + 1, c) not in S and b + 1 < Y:
            heapq.heappush(Q, (-A[a] - B[b + 1] - C[c], a, b + 1, c))
            S.add((a, b + 1, c))
        if (a, b, c + 1) not in S and c + 1 < Z:
            heapq.heappush(Q, (-A[a] - B[b] - C[c + 1], a, b, c + 1))
            S.add((a, b, c + 1))


if __name__ == "__main__":
    main()

import sys

# \n
def input():
    return sys.stdin.readline().rstrip()


def main():
    X, Y, Z, K = list(map(int, input().split()))
    A = list(map(int, input().split()))
    B = list(map(int, input().split()))
    C = list(map(int, input().split()))
    A.sort(reverse=True)
    B.sort(reverse=True)
    C.sort(reverse=True)
    L = []
    for i in range(X):
        for j in range(min(Y, K // (i + 1) + 1)):
            for k in range(min(Z, K // (i + 1) // (j + 1) + 1)):
                L.append(A[i] + B[j] + C[k])
    L.sort(reverse=True)
    for i in range(K):
        print((L[i]))


if __name__ == "__main__":
    main()

-import heapq -    Q = [] -    S = set() -    heapq.heapify(Q) -    heapq.heappush(Q, (-A[0] - B[0] - C[0], 0, 0, 0)) +    L = [] +    for i in range(X): +        for j in range(min(Y, K // (i + 1) + 1)): +            for k in range(min(Z, K // (i + 1) // (j + 1) + 1)): +                L.append(A[i] + B[j] + C[k]) +    L.sort(reverse=True) -        m, a, b, c = heapq.heappop(Q) -        print((-m)) -        if (a + 1, b, c) not in S and a + 1 < X: -            heapq.heappush(Q, (-A[a + 1] - B[b] - C[c], a + 1, b, c)) -            S.add((a + 1, b, c)) -        if (a, b + 1, c) not in S and b + 1 < Y: -            heapq.heappush(Q, (-A[a] - B[b + 1] - C[c], a, b + 1, c)) -            S.add((a, b + 1, c)) -        if (a, b, c + 1) not in S and c + 1 < Z: -            heapq.heappush(Q, (-A[a] - B[b] - C[c + 1], a, b, c + 1)) -            S.add((a, b, c + 1)) +        print((L[i]))