901A - Hashing Trees - CodeForces Solution

n = int(input())
a = list(map(int,input().split()))
k = 0
r = 0
sum1 = 0
for i in range(n+1):
    if a[i] > 1:
        k += 1
    else:
        k = 0
    if k == 2:
        r = 1
    sum1 += a[i]
if r == 0:
    print('perfect')
    exit()
r1 = []
r2 = []
num = 0
prev = 0
for i in range(n+1):
    was = 0
    for k in range(a[i]):
        r1.append(prev)
        if a[i] > 1 and a[i-1] > 1 and was == 0:
            r2.append(prev-1)
            was = 1
        else:
            r2.append(prev)
        num += 1
    prev = num
print('ambiguous')
print(*r1)
print(*r2)