#include <bits/stdc++.h>
using namespace std;
int n, x, ans = 0;
inline int read() {
  int X = 0, w = 0;
  char ch = 0;
  while (ch < '0' || ch > '9') {
    w |= ch == '-';
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9')
    X = (X << 3) + (X << 1) + (ch ^ 48), ch = getchar();
  return w ? -X : X;
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &x);
    ans += x;
  }
  printf("%d", ans - n);
  return 0;
}
