package chelper;

import io.InputReader;
import io.OutputWriter;
import misc.SimpleSavingChelperSolution;


public class TaskC extends SimpleSavingChelperSolution {

  public void solve(int testNumber, InputReader in, OutputWriter out) {
    wrapSolve(testNumber, in, out);
  }

  @Override
  public void solve(int testNumber) {
    int n = in.nextInt();
    int[] a = in.nextIntArray(n);
    
    int[] counts = new int[200];
    for (int i : a) {
      counts[i]++;
    }

    int size1 = 0;
    int size2 = 0;
    int size3Plus = 0;

    for (int count : counts) {
      if (count == 1) {
        size1++;
      }
      if (count == 2) {
        size2++;
      }
      if (count >= 3) {
        size3Plus++;
      }
    }

    if (size1 % 2 == 1 && size3Plus == 0) {
      out.println("NO");
      return;
    }

    boolean[] mask = new boolean[n];

    boolean parity = true;
    boolean shouldUse3Plus = size1 % 2 == 1;

    for (int i = 0; i < 200; i++) {
      if (counts[i] == 1) {
        for (int j = 0; j < n; j++) {
          if (a[j] == i) {
            mask[j] = parity;
          }
        }

        parity = !parity;
      }

      if (counts[i] >= 3 && shouldUse3Plus) {
        boolean first = true;

        for (int j = 0; j < n; j++) {
          if (a[j] == i) {
            mask[j] = parity == first;
            first = false;
          }
        }

        parity = !parity;
        shouldUse3Plus = false;
      }
    }


    out.println("YES");
    for (boolean b : mask) {
      out.print(b ? 'A' : 'B');
    }
  }
}