#include <bits/stdc++.h>
#define repd(i,a,b) for (int i=(a);i<(b);i++)
#define rep(i,n) repd(i,0,n)
typedef long long ll;
const int MOD = 1000000007;
const int INF = 1010000000;
const double EPS = 1e-10;
using namespace std;
//cout << fixed << setprecision(0)

int gcd(int a,b){
  if(b==0)return a;
  return gcd(b,a%b);
}

int lcm(int a,b){
  return a*b/gcd(a,b);
}

int main() { 
  int n;cin >> n;
  int ans;
  rep(i,n){
    int a;cin >> a;
    a--;
    ans += a;
  }
  cout << ans << endl;
}
