#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using VI = vector<int>;
using P = pair<int, int>;

#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, a, b) for (ll i = a; i < (ll)(b); i++)
#define ALL(a) (a).begin(),(a).end()

constexpr int INF = 1001001001;
constexpr ll LINF = 1001001001001001001ll;
constexpr int DX[] = {1, 0, -1, 0};
constexpr int DY[] = {0, 1, 0, -1};

template< typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true); }
template< typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true); }

const ll MOD = 1000000007;

int main() {
    int N, K;
    cin >> N >> K;
    VI A(N);
    REP(i, N) cin >> A[i];
    vector<vector<bool>> L(N + 1, vector<bool>(K + 1, false));
    vector<vector<bool>> R(N + 1, vector<bool>(K + 1, false));
    L[0][0] = true;
    R[N][0] = true;
    REP(i, N) {
        REP(j, K + 1) {
            L[i + 1][j] = L[i + 1][j] | L[i][j];
            if (j + A[i] <= K) L[i + 1][j + A[i]] = L[i + 1][j + A[i]] | L[i][j];
            R[N - i - 1][j] = R[N - i - 1][j] | R[N - i][j];
            if (j + A[N - 1 - i] <= K) R[N - i - 1][j + A[N - 1 - i]] = R[N - i - 1][j + A[N - 1 - i]] | R[N - i][j];
        }
    }
    if (!L[N][K]) {
        cout << -1 << endl;
        return 0;
    }
    int ans = 0;
    REP(i, N) {
        bool f = true, g = false;
        REP(j, K + 1) {
            if (L[i][j]) {
                if (R[i + 1][K - j]) f = false;
                if (j + A[i] <= K && R[i + 1][K - j - A[i]]) g = true;
            }
        }
        if (f && g) {
           // cout << i << endl;
            ans++;
        }
    }
    cout << ans << endl;
    /*
    REP(i, N + 1) {
        REP(j, K + 1) cout << L[i][j];
        cout << endl;
        REP(j, K + 1) cout << R[i][j];
        cout << endl << endl;
    }
    */
}