/* -*- coding: utf-8 -*-
 *
 * 369.cc: No.369 足し間違い - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 10000;

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int n;
  cin >> n;

  int sum = 0;
  for (int i = 0; i < n; i++) {
    int ai;
    cin >> ai;
    sum += ai;
  }

  int v;
  cin >> v;

  printf("%d\n", sum - v);
  return 0;
}