#include<bits/stdc++.h>
using namespace std;
#include <unordered_set>
#include <random>
//#define int long long
#define REP(i,m,n) for(int i=(m);i<(n);i++)
#define rep(i,n) REP(i,0,n)
#define pb push_back
#define all(a) a.begin(),a.end()
#define rall(c) (c).rbegin(),(c).rend()
#define mp make_pair
#define endl '\n'
//#define vec vector<ll>
//#define mat vector<vector<ll> >
#define fi first
#define se second
#define double long double
typedef long long ll;
typedef unsigned long long ull;
typedef pair<ll,ll> pll;
//typedef long double ld;
typedef complex<double> Complex;
const ll INF=1e9+7;
const ll MOD=998244353;
const ll inf=INF*INF;
const ll mod=MOD;
const ll MAX=20000010;
const double PI=acos(-1.0);
typedef vector<vector<ll> > mat;
typedef vector<ll> vec;


void solve(){
    ll n,k;cin>>n>>k;
    vector<ll>a(n);
    rep(i,n)cin>>a[i];
    vector<vector<ll> >dp(n+1,vector<ll>(k+1));
    dp[0][0]=1;
    rep(i,n){
        rep(j,k+1){
            if(dp[i][j]==0)continue;
            dp[i+1][j]=1;
            if(j+a[i]<=k)dp[i+1][j+a[i]]=1;
        }
    }
    vector<vector<ll> >dp2(n+1,vector<ll>(k+1));
    dp2[0][0]=1;
    reverse(all(a));
    rep(i,n){
        rep(j,k+1){
            if(dp2[i][j]==0)continue;
            dp2[i+1][j]=1;
            if(j+a[i]<=k)dp2[i+1][j+a[i]]=1;
        }
    }
    reverse(all(dp2));
    if(dp[n][k]==0){
        cout<<-1<<endl;
        return;
    }
    ll ans=0;
    rep(i,n){
        bool f=0;
        if(i==0){
            if(dp2[1][k]==1)f=1;
        }else if(i==n-1){
            if(dp[i][k]==1)f=1;
        }else{
            rep(j,k+1){
                if(dp[i][j]==1&&dp2[i+1][k-j]==1)f=1;
            }
        }
        //cout<<i<<' '<<f<<endl;
        if(!f)ans++;
    }
    cout<<ans<<endl;
}

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
}