import java.util.Scanner

var input = Scanner(System. `in`)

fun roomNumber(list: MutableList<Int>, testCase: Int, set: MutableSet<Int>){
	for(i in 1..testCase){
		var num = input.nextInt()
		list.add(num)
		set.add(num)
	}
}

fun run(){
	var yuki: Int = input.nextInt()
	var transfer: Int = input.nextInt()
	var testCase: Int = input.nextInt()
	var list: MutableList<Int> = mutableListOf()
	var set: MutableSet<Int> = mutableSetOf()

	roomNumber(list, testCase, set)

	println( (list.size - set.size) * (yuki + transfer) )
}

fun main(args: Array<String>){
	run()
}