import java.util.*;
import java.io.*;
import java.math.*;
 
public class Main{
    public static BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));
    public static final int INFI = Integer.MAX_VALUE;
    public static final long INFL = Long.MAX_VALUE;
    public static final int MOD = 1000000007;
    public static PrintWriter output = new PrintWriter(System.out);
    public static Scanner sc = new Scanner(System.in);
    public static final int [] dy4 = {0,1,0,-1};
    public static final int [] dx4 = {1,0,-1,0};
    public static ArrayList<ArrayList<Integer>> list = new ArrayList<>();
    public static ArrayList<Integer> answer = new ArrayList<>();
    public static boolean [] visited ;
    public static void main(String[] args) throws IOException{
        StringTokenizer st;
        //st = new StringTokenizer(buff.readLine());
        int N = sc.nextInt();
        int S = sc.nextInt();
        int K = sc.nextInt();
        int [] A = new int[N];
        for(int i=0;i<N;i++) A[i] = sc.nextInt();
        int min = INFI;
        int ans = -1;
        for(int i=0;i<N;i++) {
            if(Math.abs(A[i] - S) <= K && min > Math.abs(A[i] - S)) {
                min = Math.abs(A[i]-S);
                ans = i;
            }
        }
        output.print(ans == -1 ? "Unlucky!":ans+1);
        output.flush();
    }
}