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

using bitst = bitset<100001>;

int main() {
    int N, K; cin >> N >> K;
    vector<int> A(N);
    for (int i = 0; i < N; ++i) cin >> A[i];

    int B = sqrt(N), C = (N + B - 1) / B;
    vector<bitst> memo_dpl(C);
    bitst dpl; dpl[0] = 1;
    for (int i = 0; i < N; ++i) {
        if (i % B == 0) memo_dpl[i / B] = dpl;
        dpl |= dpl << A[i];
    }
    if (!dpl[K]) {
        puts("-1");
        return 0;
    }
    bitst dpr; dpr[K] = 1;
    int ans = 0;
    for (int i = C - 1; i >= 0; --i) {
        vector<bitst> memo(B);
        memo[0] = memo_dpl[i];
        for (int j = 0; j < min(B, N - i * B) - 1; ++j) {
            memo[j + 1] = memo[j] | (memo[j] << A[i * B + j]);
        }
        for (int j = min(B, N - i * B) - 1; j >= 0; --j) {
            if ((memo[j] & dpr).none()) ++ans;
            dpr = dpr | (dpr >> A[i * B + j]);
        }
    }
    cout << ans << endl;
}