#include <bits/stdc++.h>
using namespace std;
typedef int64_t lint;

int main()
{
    lint n;
    lint a;
    lint v;
    lint s=0;
    cin>>n;
    for(lint i=0;i<n;i++){
        cin>>a;
        s+=a;
    }
    cin>>v;
    cout<<s-v<<endl;
    // system("pause");
    
    
}