package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Scan()
	ss := strings.Fields(sc.Text())
	N, _ := strconv.Atoi(ss[0])
	S, _ := strconv.Atoi(ss[1])
	K, _ := strconv.Atoi(ss[2])

	min_r := -1
	min_d := 99
	for r := 1; r <= N; r++ {
		sc.Scan()
		a, _ := strconv.Atoi(sc.Text())
		d := a - S
		if d < 0 {
			d = -d
		}
		if d <= K && d < min_d {
			min_r = r
			min_d = d
		}
	}

	if min_r >= 0 {
		fmt.Println(min_r)
	} else {
		fmt.Println("Unlucky!")
	}
}