#include <bits/stdc++.h>
using namespace std;
struct comp {
  bool operator()(long long i, long long j) { return (i > j); }
} compob;
long long t, n, i, a[100005];
int main() {
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> a[i];
  }
  sort(a, a + n, compob);
  for (i = n - 1; i > 1; i--) {
    if (a[0] < a[1]) {
      a[0] += a[i];
    } else {
      a[1] += a[i];
    }
  }
  i = max(a[0] - a[1], a[1] - a[0]);
  cout << i + 1;
  return 0;
}
