import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.TreeSet;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int n = Integer.parseInt(sa[0]);
		int x = Integer.parseInt(sa[1]);
		sa = br.readLine().split(" ");
		long[] a = new long[n];
		for (int i = 0; i < n; i++) {
			a[i] = Integer.parseInt(sa[i]);
		}
		br.close();

		for (int i = 0; i < n; i++) {
			int[] dp = new int[n];
			for (int r = i + 1; r < n; r++) {
				TreeSet<Integer> set = new TreeSet<>();
				long sum = a[r];
				for (int k = r - 1; k >= i; k--) {
					if (k == i) {
						set.add(0);
						break;
					}
					sum += a[k];
					set.add(dp[k]);
					if (sum > x) {
						break;
					}
				}
				for (int j = 0; j < n; j++) {
					if (!set.contains(j)) {
						dp[r] = j;
						break;
					}
				}
			}
			for (int r = i - 1; r >= 0; r--) {
				TreeSet<Integer> set = new TreeSet<>();
				long sum = a[r];
				for (int k = r + 1; k <= i; k++) {
					if (k == i) {
						set.add(0);
						break;
					}
					sum += a[k];
					set.add(dp[k]);
					if (sum > x) {
						break;
					}
				}
				for (int j = 0; j < n; j++) {
					if (!set.contains(j)) {
						dp[r] = j;
						break;
					}
				}
			}
			if (dp[0] != dp[n - 1]) {
				System.out.println("A");
				return;
			}
		}
		System.out.println("B");
	}
}