#include <bits/stdc++.h>
using namespace std;
map<int, int> ma;
int a[205];
set<int> s;
set<int> s1;
int main() {
  int n;
  scanf("%d", &n);
  ma.clear();
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    ma[a[i]]++;
  }
  int v = 0;
  for (int i = 1; i <= n; i++)
    if (ma[a[i]] >= 3)
      s.insert(a[i]);
    else if (ma[a[i]] == 2)
      s1.insert(a[i]);
    else if (ma[a[i]] == 1)
      v++;
  string mm;
  if (s.size()) {
    puts("YES");
    int state = 1;
    if (v % 2 == 0) {
      for (int i = 1; i <= n; i++)
        if (s.count(a[i]) || s1.count(a[i]))
          printf("A");
        else {
          if (state)
            printf("A"), state = 0;
          else
            printf("B"), state = 1;
        }
      printf("\n");
    } else {
      bool flag = 1, label = 1;
      for (int i = 1; i <= n; i++)
        if (s.count(a[i])) {
          if (label) {
            mm.push_back('A');
            label = 0;
          } else
            mm.push_back('B');
        } else if (s1.count(a[i]))
          mm.push_back('A');
        else {
          if (state)
            mm.push_back('B'), state = 0;
          else
            mm.push_back('A'), state = 1;
        }
    }
    cout << mm << endl;
    return 0;
  } else if (v % 2 == 0) {
    puts("YES");
    bool state = 1;
    for (int i = 1; i <= n; i++)
      if (s1.count(a[i]))
        printf("A");
      else {
        if (state)
          printf("A"), state = 0;
        else
          printf("B"), state = 1;
      }
    printf("\n");
  } else
    puts("NO");
  return 0;
}
