#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int n;
  cin >> n;
  int *a = new int[n];
  map<int, int> mp;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    mp[a[i]]++;
  }
  int nice = 0;
  for (auto it : mp) {
    if (it.second == 1) nice++;
  }
  bool v[105];
  for (int i = 0; i < 105; i++) v[i] = false;
  bool vis[n];
  for (int i = 0; i < n; i++) vis[i] = false;
  char b[n];
  int x, w = 0;
  if (nice % 2 == 0) {
    for (int i = 0; i < n && w < nice / 2; i++) {
      if (mp[a[i]] == 1 && v[a[i]] == false) {
        w++;
        b[i] = 'A';
        v[a[i]] = true;
        vis[i] = true;
      }
    }
    w = 0;
    for (int i = 0; i < n && w < nice / 2; i++) {
      if (mp[a[i]] == 1 && v[a[i]] == false) {
        w++;
        b[i] = 'B';
        v[a[i]] = true;
        vis[i] = true;
      }
    }
  } else {
    bool ok = false;
    for (auto it : mp) {
      if (it.second > 2) {
        ok = true;
        x = it.first;
        break;
      }
    }
    if (!ok) {
      cout << "NO";
      return 0;
    }
    for (int i = 0; i < n; i++) {
      if (a[i] == x && vis[i] == false) {
        vis[i] = true;
        b[i] = 'A';
        break;
      }
    }
    for (int i = 0; i < n; i++) {
      if (a[i] == x && vis[i] == false) {
        vis[i] = true;
        b[i] = 'B';
      }
    }
    w = 0;
    for (int i = 0; i < n && w < nice / 2; i++) {
      if (mp[a[i]] == 1 && v[a[i]] == false) {
        w++;
        v[a[i]] = true;
        vis[i] = true;
        b[i] = 'A';
      }
    }
    w = 0;
    for (int i = 0; i < n && w < nice - nice / 2; i++) {
      if (mp[a[i]] == 1 && v[a[i]] == false) {
        w++;
        v[a[i]] = true;
        vis[i] = true;
        b[i] = 'B';
      }
    }
  }
  for (int i = 0; i < n; i++) {
    if (vis[i] == false) b[i] = 'A';
  }
  cout << "YES" << endl;
  for (int i = 0; i < n; i++) cout << b[i];
  return 0;
}
