include<iostream>

include<algorithm>

using namespace std;
int n,m,a[60],s,dem;
int main()
{
freopen("powersocket.inp","r",stdin);
freopen("powersocket.out","w",stdout);
cin>>n>>m;
for(int i=1;i<=n;i++) cin>>a[i];
sort(a+1,a+n+1,greater<int>());
s=a[1];dem++;
if(s>=m) dem++;
else
{
for(int i=2;i<=n;i++)
{
if(s+a[i]-1>=m)
{
s=s+a[i];
dem++;
break;
}
else {s=s+a[i]-1;dem++;}
}
}
if(s>=m) cout<<dem;
else cout<<-1;
return 0;
}