#define _USE_MATH_DEFINES
 
#include <iostream>
#include <iomanip>
#include <sstream>
 
#include <algorithm>
#include <cmath>
 
#include <string>
#include <queue>
#include <vector>
#include <complex>
#include <set>
#include <map>
#include <stack>
#include <list>

#include <valarray>

#include<cassert>//assert();
//#include <random>//xAOJ
/////////
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define P(p) cout<<(p)<<endl;
 
#define PII pair<int,int>
/////////
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
/////////
using namespace::std;
/////////
/////////

void solve(){
	LL N,A,sum,V;
	cin >> N;
	sum = 0;
	for(LL i = 0;i<N;++i){
		cin >> A;
		sum += A;
	}
	cin >> V;
	cout << sum - V << endl;
}

int main(void){
    std::cin.tie(0); 
    std::ios::sync_with_stdio(false);
    std::cout << std::fixed;//
    //cout << setprecision(16);//
	
	solve();
	
	return 0;
}