"""
[9934: 완전 이진 트리](https://www.acmicpc.net/problem/9934)
Tier: Silver 1
Category: 트리, 순회
"""
d = [[] for i in range(11)]
def dfs(l, depth):
mid = len(l) // 2
d[depth].append(l[mid])
if len(l) == 1:
return
dfs(l[:mid], depth + 1)
dfs(l[mid + 1:], depth + 1)
def solution():
n = int(input())
l = [*map(int, input().split())]
dfs(l, 0)
for i in range(n):
print(" ".join([*map(str, d[i])]))
if __name__ == '__main__':
solution()