#include <algorithm>
#include <iostream>
using namespace std;

const int MAXN = 100000;

#define FOR(i, n) for(int i = 0, __n = (n); i < __n; i++)

char T[MAXN * 8 + 8];

char S[MAXN + 2];

int main() {
  ios_base::sync_with_stdio(0);

  int n; cin >> n; cin >> T;

  int zeros = 0, ones = 0;
  FOR(i, 8*n) {
    if(T[i] == '0') zeros++;
    else ones++;
  }
  // cout << zeros << "/" << ones << endl;
  int p = 0;

  while(zeros >= ones + 2 && ones >= 3) {
    S[p++] = 'a';
    zeros -= 5;
    ones -= 3;
  }
  while(ones >= zeros + 4 && zeros >= 2) {
    S[p++] = 'w';
    zeros -= 2;
    ones -= 6;
  }
  while(ones >= zeros + 2 && zeros >= 3) {
    S[p++] = 'z';
    zeros -= 3;
    ones -= 5;
  }
  while(ones >= 4 && zeros >= 4) {
    S[p++] = 'l';
    zeros -= 4;
    ones -= 4;
  }

  if(zeros == 0 && ones == 0) cout << S << endl;
  else cout << "NIE" << endl;
}