#include<bits/stdc++.h>
using namespace std;
int main()
{
int n,m,k,i,a[80],s;
while(~scanf("%d%d%d",&n,&m,&k))
{
for(i=0;i<n;i++)
scanf("%d",&a[i]);
sort(a,a+n);
s=k;
for(i=n-1;i>=0&&a[i]>1;i--)
{
if(s>=m)
break;
s+=a[i]-1;
}
printf("%d\n",s>=m?n-i-1:-1);
}
return 0;
}
#include <string.h>
#include <iostream>
#include <algorithm>
using namespace std;
int i,n,m,k,N[55];
bool comp(int a,int b)
{
return a>b;
}
int main()
{
while(cin>>n>>m>>k&&(n||m||k))
{
memset(N,0,sizeof(N));
for(i=0;i<n;i++)
{
cin>>N[i];
}
sort(N,N+n,comp);
if(k>=m)
{
cout<<0<<endl;
continue;
}
for(i=0;i<n;i++)
{
k+=N[i];
if(k>=m)
{
cout<<i+1<<endl;
break;
}
}
if(i==n)
cout<<-1<<endl;
}
return 0;
}