#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  while (scanf("%d", &N) == 1) {
    int sum = 0;
    for (int i = 1; i <= N; ++i) {
      int t;
      scanf("%d", &t);
      sum += t - 1;
    }
    printf("%d\n", sum);
  }
  return 0;
}
