#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <sstream>
#include <utility>
#include <iomanip>
#include <tuple>
#define ll long long int
#define rep(i,x,y) for(int i=x;i<y;i++)
#define rel(i,x,y) for(int i=x-1;i>=y;i--)
#define all(x) x.begin(),x.end()
using namespace std;


int main(){
	cin.tie(nullptr);
	ios::sync_with_stdio(false);
	int n;
	cin >> n;
	vector<ll> a(n);
	rep(i,0,n) cin >> a[i];
	cout << accumulate(all(a),0)-a.size() << endl;

}
