func main()
	var n: int :: cui@inputInt()
	var k: int :: cui@inputInt()
	var a: []int :: #[n]int
	for i(0, n - 1)
		do a[i] :: cui@inputInt()
	end for
	var x: int :: 0
	var md: int :: 0
	for i(0, n - 1)
		do md :+ a[i]
	end for
	
	for i(0, n - 1)
		do x :* k
		do x :+ a[i]
		do x :% md
	end for
	
	var ans: int :: x
	do cui@print("\{ans}\n")
end func