import java.util.Scanner

fun main(args: Array<String>){
	val sc = Scanner(System.`in`)
	val N = Integer.parseInt(sc.nextLine())
	val S = sc.nextLine().split(" ")

	val A = IntArray(N)
	for(i in 0..N-1) A[i]=Integer.parseInt(S[i])

	//val m = LLCM(A) - 1
	var count = -N

	for(i in 0..N-1) count += A[i]

	println(count)

}