#include <bits/stdc++.h>
using namespace std;
const int inf = numeric_limits<int>::max() >> 2;
const long long linf = numeric_limits<long long>::max() >> 2;
const unsigned long long ulinf = numeric_limits<unsigned long long>::max() >> 2;
const double pi = acos(-1);
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
const int dx8[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
const int dy8[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
long long modpow(long long i, long long j) {
  long long tmp = 1;
  while (j) {
    if (j % 2) tmp = ((tmp * i) % (long long)(1e9 + 7));
    i = ((i * i) % (long long)(1e9 + 7));
    j /= 2;
  }
  return tmp;
}
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
vector<string> split(const string &str, char sep) {
  vector<string> v;
  stringstream ss(str);
  string buffer;
  while (getline(ss, buffer, sep)) {
    v.push_back(buffer);
  }
  return v;
}
int n;
int a[100005];
int f(int m) {
  int r = 0;
  for (int i = (0); i < (int)(n); i++) r += m % a[i];
  return r;
}
int main() {
  cin >> n;
  for (int i = 0; i < (int)(n); i++) cin >> a[i];
  ;
  int ans = -inf;
  for (int i = (1); i < (int)(100005); i++) {
    ans = max(ans, f(i));
  }
  cout << (ans) << endl;
  return 0;
}
