package main

import . "fmt"
import . "os"
import bf "bufio"

func main() {
	rd:=bf.NewReader(Stdin)
	var n int
	var k int64
	Fscan(rd,&n,&k)
	a:=make([]int64,n)
	var m int64
	for i:=range a {
		Fscan(rd,&a[i])
		m+=a[i]
	}
	var x int64
	for _,v:=range a {
		x=x*k%m
		x=(x+v)%m
	}
	Println(x)
}