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

#define rep(i, f, n) for (int i = (f); i < (n); i++)
#define rrep(i, f, n) for (int i = int(n) - 1; i >= f; i--)
typedef long long ll;
typedef pair<int, int> P;

template <typename T, typename U>
auto Sum(T a, U b) -> decltype(a + b)
{
    return a + b;
}

template <typename T, typename U>
inline bool amax(T &a, U b)
{
    if (b > a)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T, typename U>
inline bool amin(T &a, U b)
{
    if (b < a)
    {
        a = b;
        return true;
    }
    return false;
}

int main()
{
    int N, K;
    cin >> N >> K;
    vector<int> A(N + 1);
    rep(i, 1, N + 1) cin >> A[i];

    bool dpl[N + 2][K + 1], dpr[N + 2][K + 1];
    rep(i, 0, N + 2) rep(j, 0, K + 2)
    {
        dpl[i][j] = false;
        dpr[i][j] = false;
    }
    dpl[0][0] = true;
    dpr[N + 1][0] = true;
    rep(i, 1, N + 1) rep(j, 0, K + 1)
    {
        dpl[i][j] = dpl[i - 1][j];
        if (j >= A[i])
            dpl[i][j] |= dpl[i - 1][j - A[i]];
    }
    rrep(i, 1, N + 1) rep(j, 0, K + 1)
    {
        dpr[i][j] = dpr[i + 1][j];
        if (j >= A[i])
            dpr[i][j] |= dpr[i + 1][j - A[i]];
    }

    if (!dpl[N][K])
    {
        cout << -1 << endl;
        return 0;
    }
    int ans = 0;
    rep(i, 1, N + 1)
    {
        bool ok = true;
        rep(j, 0, K + 1)
        {
            if (dpl[i - 1][j] && dpr[i + 1][K - j])
                ok = false;
        }
        if (ok)
            ans++;
    }
    cout << ans << endl;
}