#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline string toString(T a) {
  ostringstream os("");
  os << a;
  return os.str();
}
template <typename T>
inline long long toLong(T a) {
  long long res;
  istringstream os(a);
  os >> res;
  return res;
}
template <typename T>
inline int toInt(T a) {
  int res;
  istringstream os(a);
  os >> res;
  return res;
}
template <typename T>
inline double toDouble(T a) {
  double res;
  istringstream os(a);
  os >> res;
  return res;
}
template <typename T>
inline T SQ(T a) {
  return a * a;
}
template <typename T>
inline T GCD(T a, T b) {
  if (b == 0)
    return a;
  else
    return GCD(b, a % b);
}
template <typename T>
inline T LCM(T a, T b) {
  long long res = a * b;
  res /= GCD(a, b);
  return res;
}
template <typename T>
inline unsigned long long BIGMOD(T a, T b, T m) {
  if (b == 0)
    return 1;
  else if (b % 2 == 0)
    return SQ(BIGMOD(a, b / 2, m)) % m;
  else
    return (a % m * BIGMOD(a, b - 1, m)) % m;
}
template <typename T>
inline vector<string> PARSE(T str) {
  vector<string> res;
  string s;
  istringstream os(str);
  while (os >> s) res.push_back(s);
  return res;
}
template <typename T>
inline unsigned long long DIST(T A, T B) {
  unsigned long long res =
      (A.x - B.x) * (A.x - B.x) + (A.y - B.y) * (A.y - B.y);
  return res;
}
template <typename T>
inline long long CROSS(T A, T B, T C) {
  return (B.x - A.x) * (C.y - A.y) - (C.x - A.x) * (B.y - A.y);
}
template <typename T>
inline double cosAngle(T a, T b, T c) {
  double res = a * a + b * b - c * c;
  res = res / (2 * a * b);
  res = acos(res);
  return res;
}
template <typename T>
inline T POWER(T base, int po) {
  T res = 1;
  if (base == 0) return 0;
  for (int i = (0); i < (po); i++) res *= base;
  return res;
}
template <typename T>
inline bool IS_ON(T mask, T pos) {
  return mask & (1 << pos);
}
template <typename T>
inline int OFF(T mask, T pos) {
  return mask ^ (1 << pos);
}
template <typename T>
inline int ON(T mask, T pos) {
  return mask | (1 << pos);
}
template <typename T>
inline bool INSIDE_GRID(int R, int C, int ro, int clm) {
  if (R >= 0 && C >= 0 && R < ro && C < clm) return 1;
  return 0;
}
template <typename T>
inline void PRINT_GRID(T GRID, int ro, int clm) {
  cout << "GRID"
       << ": " << GRID << endl;
  for (int i = (0); i < (ro); i++) {
    for (int j = (0); j < (clm); j++) cout << GRID[i][j] << " ";
    puts("");
  }
}
int arr[500005];
string s, t;
int g[110][110];
int check(int lena, int lenb) {
  int r = lena + 1, c = lenb + 1;
  for (int i = 0; i < r; i++) {
    g[i][0] = 0;
  }
  for (int i = 0; i < c; i++) g[0][i] = 0;
  for (int i = 1; i < r; i++)
    for (int j = 1; j < c; j++) {
      if (s[i - 1] == t[j - 1]) {
        g[i][j] = g[i - 1][j - 1] + 1;
      } else
        g[i][j] = max(g[i - 1][j], g[i][j - 1]);
    }
  return g[r - 1][c - 1] == lenb;
}
int main() {
  cin >> s >> t;
  string ss = s, tt = t;
  int len = s.size();
  if (check(len, t.size())) {
    cout << "automaton";
  } else {
    sort((ss).begin(), (ss).end());
    sort((tt).begin(), (tt).end());
    s = ss;
    t = tt;
    if (ss == tt)
      cout << "array";
    else if (check(ss.size(), tt.size()))
      cout << "both";
    else
      cout << "need tree";
  }
  return 0;
}
