#include <iostream>
#include <cmath>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <tuple>
#include <cstdint>
#include <cstdio>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <deque>
#include <unordered_map>
#include <unordered_set>
#include <bitset>
#include <cctype>
#include <climits>
#include <functional>
#include <cassert>
#include <numeric>
#define rep(i, n) for(int i = 0; i < (n); i++)
#define per(i, n) for(int i = (n) - 1; i >= 0; i--)
using ll = long long;
#define vi vector<int>
#define vvi vector<vi>
#define vl vector<ll>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define mod 1000000007
using namespace std;
template<class T, class U>
bool chmax(T &a, const U &b){ return a < b ? (a = b, 1) : 0; }
template<class T, class U>
bool chmin(T &a, const U &b){ return a > b ? (a = b, 1) : 0; }
int main(){
  int n,K;
  cin >> n >> K;
  vi a(n);
  rep(i, n) cin >> a[i];
  vi dp(K + 1), cnt(K + 1);
  dp[0] = 1;
  rep(i, n){
    if(!a[i]) continue;
    cnt[a[i]]++;
    for(int j = K - a[i]; j >= 0; j--) dp[j+a[i]] += dp[j];
  }
  if(!dp[K]){
    cout << "-1\n";
    return 0;
  }
  int ans = 0;
  for(int i = 1; i <= K; i++){
    int v = cnt[i] * i;
    if(!v || v > K) continue;
    vi t = dp;
    rep(j, K+1-v) t[j+v] -= t[j];
    if(!t[K]) ans += cnt[i];
  }
  cout << ans << "\n";
}