package yukicoder;

import java.io.BufferedReader;
import java.io.InputStreamReader;

public class No369TashiMachigai {

    public static void main(String[] args) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int times = Integer.parseInt(br.readLine());
        String[] nums = br.readLine().split(" ");
        
        int num = 0;
        for(int i = 0; i < nums.length; i++) {
            num += Integer.parseInt(nums[i]);
        }
        
        int ans = num - Integer.parseInt(br.readLine());
        System.out.println(ans);
    }

}