package main

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

const MOD = 998244353

func power(base, exp int64) int64 {
	res := int64(1)
	base %= MOD
	for exp > 0 {
		if exp%2 == 1 {
			res = (res * base) % MOD
		}
		base = (base * base) % MOD
		exp /= 2
	}
	return res
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1024*1024), 1024*1024*10)

	if !scanner.Scan() {
		return
	}
	n, _ := strconv.ParseInt(scanner.Text(), 10, 64)

	scanner.Scan()
	m, _ := strconv.ParseInt(scanner.Text(), 10, 64)

	scanner.Scan()
	c, _ := strconv.ParseInt(scanner.Text(), 10, 64)

	ans := int64(1)
	prev := int64(0)
	var b int64

	for i := int64(0); i < m; i++ {
		scanner.Scan()
		b, _ = strconv.ParseInt(scanner.Text(), 10, 64)
		l := b - prev
		term := (power(c, l) + power(c, 2*l)) % MOD
		ans = (ans * term) % MOD
		prev = b
	}

	rem := n - 2*b
	ans = (ans * power(c, rem)) % MOD
	ans = (ans * power(power(2, m), MOD-2)) % MOD

	fmt.Println(ans)
}