884 B | 846 chars
"""
[6526: 모호한 순열](https://www.acmicpc.net/problem/6526)
Tier: Bronze 1
Category: 구현
그냥 인덱스를 저장하면 된다.
"""
import sys
from math import sqrt, pi, sin, factorial, ceil, floor
from datetime import datetime, timedelta
sys.setrecursionlimit(10**7)
BLANK = " "
# inp = input
inp = lambda : sys.stdin.readline().rstrip()
mii = lambda x = BLANK : [*map(int,inp().split(x))]
mfi = lambda x = BLANK : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
while 1:
n = ii()
if n == 0:
break
l = mii()
idx = [0] * n
for i in range(n):
idx[l[i] - 1] = i + 1
for i in range(n):
if idx[i] != l[i]:
p(end="not ")
break
p("ambiguous")
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()