package main

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

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	N := nextInt(sc)
	sum := 0
	for i := 0; i < N; i++ {
		sum += nextInt(sc)
	}
	v := nextInt(sc)
	fmt.Println(sum - v)

}