n = int(input())
a = []
p = []
for i in range(n):
    a.append(list(map(int,input().split())))
    p.append(a[i][0])
ans = []
for i in range(max(p)):
    for j in range(n):
        if len(a[j]) != 1:
            ans.append(a[j][1])
            a[j].pop(1)
print(' '.join(map(str, ans)))