#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> pii;
#define pb push_back
#define mp make_pair
#define fi first
#define se second

int main()
{
	int n,a;
	ll sum=0,ans;
	cin>>n;
	for(int i=0;i<n;i++)
	{
		cin>>a;
		sum+=a;
	}
	cin>>ans;
	cout<<sum-ans<<endl;
	return 0;
}