n = int(input())
line = [[] for _ in range(1000)]
for _ in range(n):
    l = list(input().split())
    p = int(l[0])
    for j in range(p):
        line[j].append(int(l[j+1]))
ret = []
i = 0
while True:
    if not line[i]:
        break
    else:
        for c in line[i]:
            ret.append(c)
    i += 1
print(*ret)