Alice and Bob love playing one-dimensional battle ships. They play on the field in the form of a line consisting of n square cells (that is, on a 1 × n table).

At the beginning of the game Alice puts k ships on the field without telling their positions to Bob. Each ship looks as a 1 × a rectangle (that is, it occupies a sequence of a consecutive squares of the field). The ships cannot intersect and even touch each other.

After that Bob makes a sequence of "shots". He names cells of the field and Alice either says that the cell is empty ("miss"), or that the cell belongs to some ship ("hit").

But here's the problem! Alice like to cheat. May be that is why she responds to each Bob's move with a "miss". 

Help Bob catch Alice cheating — find Bob's first move, such that after it you can be sure that Alice cheated.

Input

The first line of the input contains three integers: n, k and a (1 ≤ n, k, a ≤ 2·105) — the size of the field, the number of the ships and the size of each ship. It is guaranteed that the n, k and a are such that you can put k ships of size a on the field, so that no two ships intersect or touch each other.

The second line contains integer m (1 ≤ m ≤ n) — the number of Bob's moves.

The third line contains m distinct integers x1, x2, ..., xm, where xi is the number of the cell where Bob made the i-th shot. The cells are numbered from left to right from 1 to n.

Output

Print a single integer — the number of such Bob's first move, after which you can be sure that Alice lied. Bob's moves are numbered from 1 to m in the order the were made. If the sought move doesn't exist, then print "-1".

Examples

Input

11 3 3
5
4 8 6 1 11


Output

3


Input

5 1 3
2
1 5


Output

-1


Input

5 1 3
1
3


Output

1
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;

public class Main {
	public static void main(String[] args) throws IOException {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;

		// InputStream inputStream = new FileInputStream("joke.in");
		// OutputStream outputStream = new FileOutputStream("joke.out");

		InputReader in = new InputReader(inputStream);
		OutputWriter out = new OutputWriter(outputStream);

		TaskB solver = new TaskB();
		solver.solve(in, out);

		out.close();
	}
}

class TaskB {

	public void solve(InputReader in, OutputWriter out) {

		n = in.nextInt();
		k = in.nextInt();
		a = in.nextInt();
		int m = in.nextInt();

		int cnt = f(n);
		TreeSet<Segment> set = new TreeSet<Segment>();
		set.add(new Segment(1, n));

		for (int i = 0; i < m; i++) {
			int x = in.nextInt();
			Segment s = new Segment(x, x);
			Segment seg = set.floor(s);
			
			//if(seg==null) continue;
			cnt -= f(seg.r - seg.l + 1);
			set.remove(seg);
			if (seg.l < x) {
				cnt += f(x - seg.l);
				set.add(new Segment(seg.l, x - 1));
			}

			if (seg.r > x) {
				cnt += f(seg.r - x);
				set.add(new Segment(x + 1, seg.r));
			}
			if(cnt<k){
				out.write(i+1);
				return;
			}
		}
		
		out.write(-1);
	}

	int n, k, a;

	int f(int len) {
		int ans = len / (a + 1);
		if (len % (a + 1) == a)
			ans++;

		return ans;
	}

}

class Segment implements Comparable<Segment> {

	public Segment(int l, int r) {
		this.l = l;
		this.r = r;
	}

	public int compareTo(Segment s) {
		return l-s.l;
	}

	int l, r;
}

class InputReader {

	BufferedReader reader;
	StringTokenizer tokenizer;

	public InputReader(InputStream stream) {
		tokenizer = null;
		reader = new BufferedReader(new InputStreamReader(stream));
	}

	public String next() {
		while (tokenizer == null || !tokenizer.hasMoreTokens()) {
			try {
				tokenizer = new StringTokenizer(reader.readLine());
			} catch (IOException e) {
				throw new RuntimeException();
			}
		}

		return tokenizer.nextToken();
	}

	public String nextLine() {
		tokenizer = null;
		try {
			return reader.readLine();
		} catch (IOException e) {
			throw new RuntimeException();
		}
	}

	public int nextInt() {
		return Integer.parseInt(next());
	}

	public long nextLong() {
		return Long.parseLong(next());
	}

	public double nextDouble() {
		return Double.parseDouble(next());
	}

	public int[] nextIntArray(int n) {
		int[] res = new int[n];
		for (int i = 0; i < n; i++)
			res[i] = nextInt();

		return res;
	}

}

class OutputWriter {

	PrintWriter out;

	public OutputWriter(OutputStream stream) {
		out = new PrintWriter(
				new BufferedWriter(new OutputStreamWriter(stream)));
	}

	public void write(Object... o) {
		for (Object cur : o)
			out.print(cur);
	}

	public void writeln(Object... o) {
		write(o);
		out.println();
	}

	public void flush() {
		out.flush();
	}

	public void close() {
		out.close();
	}

}
