#!/usr/bin/env python3
n = int(input())
a = [None] * n
for i in range(n):
    _, *a[i] = map(int, input().split())
ans = []
cur = [(i, 0) for i in range(n)]
while cur:
    nxt = []
    for i, j in cur:
        if j >= len(a[i]):
            continue
        ans += [a[i][j]]
        nxt += [(i, j + 1)]
    cur = nxt
print(*ans)