#include <bits/stdc++.h>
using namespace std;
const long long INF = ((1LL << 30) + (1LL << 29));
const long long MOD = 1000000007;
long long N;
vector<long long> A;
void input() {
  cin >> N;
  A.resize(N);
  for (long long i = 0; i < (long long)(N); ++i) {
    cin >> A[i];
  }
}
void solve() {
  long long ans = 0;
  for (auto x : A) {
    ans += (x - 1);
  }
}
signed main() {
  input();
  solve();
  return 0;
}
