#include <bits/stdc++.h>
using namespace std;
template <class S, class T>
istream& operator>>(istream& is, pair<S, T>& p) {
  return is >> p.first >> p.second;
}
const double EPS = 1e-10;
const double PI = acos(-1.0);
const long long MOD = 1e9 + 7;
int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  int N;
  cin >> N;
  vector<long long> xs(N);
  for (int i = (0); i < (N); ++i) cin >> xs[i];
  sort((xs).begin(), (xs).end());
  long long ans =
      xs.back() + xs.back() - accumulate((xs).begin(), (xs).end(), 0LL);
  cout << ans + 1 << endl;
  return 0;
}
