source_code: import java.awt.Point;
  import java.io.*;
  import java.math.BigInteger;
  import java.util.*;
  import static java.lang.Math.*;
  
  public class A {
  
  	final boolean ONLINE_JUDGE = System.getProperty("ONLINE_JUDGE") != null;
  	BufferedReader in;
  	PrintWriter out;
  	StringTokenizer tok = new StringTokenizer("");
  
  	void solve() throws IOException {
  		int n = readInt();
  		int m = readInt();
  		int k = readInt();
  		int[] a = readArr(n);
  		Arrays.sort(a);
  		for(int i = 0; i <= n; i++){
  			int curR = k;
  			for(int j = n-1; j >= n-i; j--){
  				curR += a[j];
  			}
  			curR -= i;
  			if(curR >= m){
  				out.println(i);
  				return;
  			}
  		}
  		out.println(-1);
  	}
  
  	void init() throws FileNotFoundException {
  		if (ONLINE_JUDGE) {
  			in = new BufferedReader(new InputStreamReader(System.in));
  			out = new PrintWriter(System.out);
  		} else {
  			in = new BufferedReader(new FileReader("input.txt"));
  			out = new PrintWriter("output.txt");
  		}
  	}
  
  	String readString() throws IOException {
  		while (!tok.hasMoreTokens()) {
  			tok = new StringTokenizer(in.readLine());
  		}
  		return tok.nextToken();
  	}
  
  	int readInt() throws IOException {
  		return Integer.parseInt(readString());
  	}
  
  	long readLong() throws IOException {
  		return Long.parseLong(readString());
  	}
  
  	double readDouble() throws IOException {
  		return Double.parseDouble(readString());
  	}
  
  	int[] readArr(int n) throws IOException {
  		int[] res = new int[n];
  		for (int i = 0; i < n; i++) {
  			res[i] = readInt();
  		}
  		return res;
  	}
  
  	long[] readArrL(int n) throws IOException {
  		long[] res = new long[n];
  		for (int i = 0; i < n; i++) {
  			res[i] = readLong();
  		}
  		return res;
  	}
  
  	public static void main(String[] args) {
  		new A().run();
  	}
  
  	public void run() {
  		try {
  			long t1 = System.currentTimeMillis();
  			init();
  			solve();
  			out.close();
  			long t2 = System.currentTimeMillis();
  			System.err.println("Time = " + (t2 - t1));
  		} catch (Exception e) {
  			e.printStackTrace(System.err);
  			System.exit(-1);
  		}
  	}
  }