n = int(input())

L = [[] for i in range(n)]
for i in range(n):
    a = list(map(int,input().split()))
    p = a[0]
    a = a[1:]
    for i in range(p):
        L[i].append(a[i])

ans = []
for i in range(n):
    for j in L[i]:
        ans.append(j)
        
for i in ans:
    print(i,end=" ")