#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#include "bits/stdc++.h"

using namespace std;

using i64 = long long;

template<typename T>
struct Segtree{
    int n;
    T op;
    vector<T> elm;
    function<T(T, T)> f;

    Segtree(int n, T init, function<T(T, T)> f, T op = T()) :
        n(n),
        op(op),
        elm(2 * n, init),
        f(f)
    {
        for(int i = n - 1; i >= 1; --i)
            elm[i] = f(elm[2 * i], elm[2 * i + 1]);
    }

    Segtree(int n, vector<T> init, function<T(T, T)> f, T op = T()) :
        n(n),
        op(op),
        elm(2 * n),
        f(f)
    {
        for(int i = 0; i < n; ++i)
            elm[i + n] = init[i];
        for(int i = n - 1; i >= 1; --i)
            elm[i] = f(elm[2 * i], elm[2 * i + 1]);
    }

    void set(int x, T val){
        x += n;
        elm[x] = val;
        while(x >>= 1)
            elm[x] = f(elm[2 * x], elm[2 * x + 1]);
    }

    void update(int x, T val){
        x += n;
        elm[x] = f(elm[x], val);
        while(x >>= 1)
            elm[x] = f(elm[2 * x], elm[2 * x + 1]);
    }

    T get(int x, int y) const{
        T l = op, r = op;
        for(x += n, y += n - 1; x <= y; x >>= 1, y >>= 1){
            if(x & 1)
                l = f(l, elm[x++]);
            if(!(y & 1))
                r = f(elm[y--], r);
        }
        return f(l, r);
    }
};


signed main(){
    int n, x;
    cin >> n >> x;
    vector<int> v(n);
    for(auto& w : v)
        cin >> w;

    vector<i64> r(n + 1, 0);
    for(int i = 0; i < n; ++i)
        r[i + 1] = r[i] + v[i];

    vector<int> nex(n, n), prev(n, 0);
    for(int i = 0; i < n; ++i){
        auto it = upper_bound(r.begin(), r.end(), r[i] + x);
        int idx = distance(r.begin(), it);
        nex[i] = min(idx, n);
        auto it2 = lower_bound(r.begin(), r.end(), r[i + 1] - x);
        idx = distance(r.begin(), it2);
        prev[i] = max(0, idx - 1);
    }
    /*
    for(auto& x : nex)
        cout << x << " ";
    cout << endl;
    for(auto& x : prev)
        cout << x << " ";
    cout << endl;
     */

    vector<Segtree<int>> a(n, Segtree<int>(n, 0, [](auto x, auto y){return x + y;}, 0));
    vector<Segtree<int>> b(n, Segtree<int>(n, 0, [](auto x, auto y){return x + y;}, 0));

    for(int k = 1; k < n; ++k)
        for(int i = 0, j = k; j < n; ++i, ++j){
            bool f = false;
            // TODO: set len

            // dp[i][j] : dp[i][j - x, j)
            // cout << j - prev[j] << "   " << nex[i] - (i + 1) << "    ";
            f |= (a[i].get(max(i, prev[j]), j) != (j - max(i, prev[j])));

            // dp[i][j] : dp[i, i + x][j, j)
            f |= (b[j].get(i + 1, min(nex[i], j + 1)) != (min(nex[i], j + 1) - (i + 1)));
            if(f){
                a[i].update(j, 1);
                b[j].update(i, 1);
            }
            /*
            cout << "[" << i << ",[" << max(i, prev[j]) << "," << j - 1 << "]]  : ";
            cout << "[[" << i + 1 << "," << min(nex[j], j + 1) - 1 << "]," << j << "]  : ";
            cout << "[" << i << "," << j << "] -> " << (f ? "Win" : "Lose") << endl;
             */
        }

    /*
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n; ++j)
            cout << a[i].sum(j, j + 1) << " \n"[j == n - 1];
    }
    cout << endl;
     */
    cout << (a[0].get(n - 1, n) ? "A" : "B") << endl;
}