#include<bits/stdc++.h>
#include<atcoder/all>
namespace my{
using namespace std;
#define done(...) return pp(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;lin(__VA_ARGS__)
#define VRD(T,n,...) vec<T>__VA_ARGS__;setsize({n},__VA_ARGS__);lin(__VA_ARGS__)
#define FO(n) for(ll ij=n;ij--;)
#define FOR(i,...) for(auto[i,i##stop,i##step]=range(0,__VA_ARGS__);i<i##stop;i+=i##step)
#define fo(i,...) FO##__VA_OPT__(R)(i __VA_OPT__(,__VA_ARGS__))
#define of(i,...) for(auto[i,i##stop,i##step]=range(1,__VA_ARGS__);i>=i##stop;i-=i##step)
#define fe(a,i,...) for(auto&&__VA_OPT__([)i __VA_OPT__(,__VA_ARGS__]):a)
#define single_testcase void solve();}int main(){my::io();my::solve();}namespace my{
void io(){cin.tie(nullptr)->sync_with_stdio(0);cout<<fixed<<setprecision(15);}
using ll=long long;
template<class...A>auto range(bool s,A...a){array<ll,3>r{0,0,1};ll I=0;((r[I++]=a),...);if(!s&&I==1)swap(r[0],r[1]);r[0]-=s;return r;}
constexpr char nl=10;
constexpr char sp=32;
auto ceil(auto x,auto y){if(y<0)x=-x,y=-y;return x<=0?x/y:(x-1)/y+1;}
auto min(const auto&...a){return min(initializer_list<common_type_t<decltype(a)...>>{a...});}

template<class A,class B>struct pair{
  A a;B b;
  pair()=default;
  pair(A a,B b):a(a),b(b){}
  pair(const std::pair<A,B>&p):a(p.first),b(p.second){}
  auto operator<=>(const pair&)const=default;
  friend ostream&operator<<(ostream&o,const pair&p){return o<<p.a<<sp<<p.b;}
};

template<class T,class U>ostream&operator<<(ostream&o,const std::pair<T,U>&p){return o<<p.first<<sp<<p.second;}

template<class V>concept vectorial=is_base_of_v<vector<typename V::value_type>,V>;
template<class T>struct vec_attr{using core_type=T;static constexpr int d=0;};
template<vectorial V>struct vec_attr<V>{using core_type=typename vec_attr<typename V::value_type>::core_type;static constexpr int d=vec_attr<typename V::value_type>::d+1;};
template<class T>using core_t=vec_attr<T>::core_type;
template<class V>istream&operator>>(istream&i,vector<V>&v){fe(v,e)i>>e;return i;}
template<class V>ostream&operator<<(ostream&o,const vector<V>&v){fe(v,e)o<<e<<string(&e!=&v.back(),vectorial<V>?nl:sp);return o;}

template<class V>struct vec:vector<V>{
  using vector<V>::vector;
  vec(const vector<V>&v){vector<V>::operator=(v);}

  vec&operator^=(const vec&u){this->insert(this->end(),u.begin(),u.end());return*this;}
  vec operator^(const vec&u)const{return vec{*this}^=u;}
  vec&operator++(){fe(*this,e)++e;return*this;}
  vec&operator--(){fe(*this,e)--e;return*this;}

  auto scan(const auto&f)const{pair<core_t<V>,bool>r{};fe(*this,e)if constexpr(!vectorial<V>)r.b?f(r.a,e),r:r={e,1};else if(auto s=e.scan(f);s.b)r.b?f(r.a,s.a),r:r=s;return r;}
  auto min()const{return scan([](auto&a,const auto&b){a>b?a=b:0;;}).a;}
};
template<class T=ll,size_t n,size_t i=0>auto make_vec(const ll(&s)[n],T x={}){if constexpr(n==i+1)return vec<T>(s[i],x);else{auto X=make_vec<T,n,i+1>(s,x);return vec<decltype(X)>(s[i],X);}}
template<ll n,class...A>void setsize(const ll(&l)[n],A&...a){((a= make_vec(l,core_t<A>())),...);}

void lin(auto&...a){(cin>>...>>a);}
template<char c=sp>void pp(const auto&...a){ll n=sizeof...(a);((cout<<a<<string(--n>0,c)),...);cout<<nl;}

uint64_t kth_root_floor(uint64_t a,ll k){
  if (k==1)return a;
  auto within=[&](uint32_t x){uint64_t t=1;fo(k)if(__builtin_mul_overflow(t,x,&t))return false;return t<=a;};

  uint64_t r=0;
  of(i,sizeof(uint32_t)*CHAR_BIT)if(within(r|(1u<<i)))r|=1u<<i;
  return r;
}
auto sqrt_floor(auto x){return kth_root_floor(x,2);}

single_testcase
void solve(){
  LL(N,K);
  VRD(int,N,a);

  ll block_size=sqrt_floor(N);
  ll block_num=ceil(N,block_size);

  using bitv=bitset<100001>;

  vec<bitv>mem(block_num);
  bitv cu;
  cu[0]=1;
  fo(i,N){
    if(i%block_size==0)mem[i/block_size]=cu;
    cu|=cu<<a[i];
  }
  if(cu[K]==0)done(-1);

  ll ans=0;
  cu=bitv{};
  cu[K]=1;
  of(i,block_num){
    vec<bitv>dp(min(block_size,N-i*block_size)); // dp[j]:a[i*block_size+j-1]以前の結果
    dp[0]=mem[i];
    fo(j,dp.size()-1)dp[j+1]=dp[j]<<a[i*block_size+j]|dp[j];

    of(j,dp.size()){
      // a[i*block_size+j]を使わずにKにできるか
      if((dp[j]&cu).count()==0)++ans; // cu:a[i*block_size+j+1]以降の結果
      cu|=cu>>a[i*block_size+j];
    }
  }
  pp(ans);
}}