#include <bits/stdc++.h>
using namespace std;
long long power(long long x, long long y) {
  if (y == 0) return 1;
  long long t = power(x, y / 2);
  if (y % 2 == 0)
    return t * t;
  else
    return t * t * x;
}
long long max(long long a, long long b) {
  if (a > b) return a;
  return b;
}
long long min(long long a, long long b) {
  if (a < b) return a;
  return b;
}
int main() {
  long long h;
  cin >> h;
  long long a[h + 4];
  a[0] = 1;
  long long status = 0;
  for (long long i = 1; i < h + 2; i++) {
    cin >> a[i];
    if (a[i] != 1 && a[i - 1] != 1) {
      status = 1;
    }
  }
  a[0] = 0;
  if (status == 0)
    cout << "perfect";
  else {
    cout << "ambiguous" << endl;
    long long nodes = 0, left = 0, right = 0;
    for (long long i = 1; i < h + 2; i++) {
      nodes += a[i];
      for (long long j = 0; j < a[i]; j++) {
        cout << (nodes - a[i]) << " ";
      }
    }
    cout << endl;
    nodes = 0;
    for (long long i = 1; i < h + 2; i++) {
      for (long long j = 0; j < a[i]; j++) {
        if (j < a[i] / 2)
          cout << left << " ";
        else
          cout << (nodes) << " ";
      }
      left = nodes + 1;
      nodes += a[i];
    }
  }
}
