#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  constexpr int K = 100000, B = 316;
  int n, k; cin >> n >> k;
  vector<int> a(n); REP(i, n) cin >> a[i];
  const int b = (n + B - 1) / B;
  vector<bitset<K + 1>> ls(b);
  bitset<K + 1> l(1), r(0);
  REP(i, n) {
    if (i % B == 0) ls[i / B] = l;
    l |= l << a[i];
  }
  if (!l[k]) {
    cout << "-1\n";
    return 0;
  }
  int ans = 0;
  r.set(k);
  for (int block = b - 1; block >= 0; --block) {
    const int start = block * B, end = min((block + 1) * B, n);
    vector<bitset<K + 1>> tmp(end - start);
    l = ls[block];
    FOR(i, start, end) {
      tmp[i - start] = l;
      l |= l << a[i];
    }
    for (int i = end - 1; i >= start; --i) {
      if ((tmp[i - start] & r).count() == 0) ++ans;
      r |= r >> a[i];
    }
  }
  cout << ans << '\n';
  return 0;
}