#include<iostream>
#include<map>
#include<vector>
using namespace std;
int main(){
	int N;
	cin >> N;
  	int c;
	vector<int> a;
  	rep(i,N){
      cin >> c;
      a.push_back(c);
    }
  
	long long sum = 0;
	for(auto x:a) sum+=x-1;
	cout << sum << endl;
}
