N = int(input())
p = list(map(int, input().split()))
prev = [-1] + list(range(N-1))
next = list(range(1, N)) + [-1]

sorted_args = sorted(range(N), key=lambda x: p[x])
left = [True]*N

ans = []

for x in sorted_args:
    if not left[x]:
        continue
    if next[x] == -1:
        continue
    y = next[x]

    left[x] = False
    left[y] = False
    pr = prev[x]
    n = next[y]
    if pr != -1:
        next[pr] = n
    if n != -1:
        prev[n] = pr
    
    ans.extend([p[x], p[y]])
print(*ans)