package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	var n, a, v, sum int
	sc.Scan()
	n, _ = strconv.Atoi(sc.Text())
	for i := 0; i < n; i++ {
		sc.Scan()
		a, _ = strconv.Atoi(sc.Text())
		sum += a
	}
	sc.Scan()
	v, _ = strconv.Atoi(sc.Text())
	fmt.Println(sum - v)
}