#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
const int maxn = 1e6 + 5;
long long int power(long long int base, long long int exp) {
  long long int res = 1;
  while (exp) {
    if (exp % 2) res *= base;
    base *= base;
    res %= mod;
    base %= mod;
    exp /= 2;
  }
  return res;
}
int arr[maxn], level[maxn], ans1[maxn], ans2[maxn];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int n, i, j;
  cin >> n;
  bool flag = 1;
  int tot = 0;
  for (i = 0; i <= n; i++) {
    cin >> arr[i];
    if (arr[i] > 1 && arr[i - 1] > 1) {
      flag = 0;
    }
    tot += arr[i];
  }
  if (flag) {
    cout << "perfect";
  } else {
    cout << "ambiguous"
         << "\n";
    int cnt = 2;
    level[0] = 1;
    for (i = 1; i <= n; i++) {
      if (!level[i]) {
        level[i] = cnt;
      }
      for (j = 1; j <= arr[i]; j++) {
        ans1[cnt++] = level[i - 1];
      }
    }
    cnt = 2;
    memset(level, 0, sizeof(level));
    level[0] = 1;
    for (i = 1; i <= n; i++) {
      if (!level[i]) {
        level[i] = cnt;
      }
      for (j = 1; j <= arr[i]; j++) {
        if (arr[i - 1] > 1 && arr[i] > 1 && j == 1) {
          ans2[cnt++] = level[i - 1] + 1;
          continue;
        }
        ans2[cnt++] = level[i - 1];
      }
    }
    for (i = 1; i <= tot; i++) {
      cout << ans1[i];
      if (i != tot)
        cout << " ";
      else
        cout << "\n";
    }
    for (i = 1; i <= tot; i++) {
      cout << ans2[i];
      if (i != tot)
        cout << " ";
      else
        cout << "\n";
    }
  }
  return 0;
}
