num_row = int(input())

arr = [[int(x) for x in reversed(input().split(' '))] for _ in range(0, num_row)]
ans = []

for lis in arr:
    lis.pop()

for _ in range(0, 101):
    for lis in arr:
        if len(lis) > 0:
            ans.append(lis.pop())

print(' '.join(map(str, ans)))