#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int n;
  cin >> n;
  vector<long long> l(n);
  for (auto i = 0; (i) < (n); ++i) cin >> l[i];
  sort((l).begin(), (l).end());
  long long a = 0, b = 0, c = 0;
  a = l[0];
  c = l[n - 1];
  int i = 1, j = n - 2;
  do {
    a += l[i++];
    if (a > c && i <= j) c += l[j--];
  } while (i <= j);
  cout << abs(c - a) + 1;
  return 0;
}
