from sys import stdin

def main():
    input = lambda: stdin.readline()[:-1]
    N = int(input())
    A = [[''] * 100 for _ in [0] * N]
    for i in range(N):
        s = input().split()
        j = int(s[0])
        A[i][:j] = s[1:]

    ans = ''
    for s in list(zip(*A)):
        ans += ''.join(s)
    print(*ans)

main()