#include <bits/stdc++.h>
using namespace std;
int main() {
  long long i, j, k, l, m, n, a[300001], dp1[300001], temp;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> m;
    a[i] = m;
  }
  sort(a, a + n);
  dp1[0] = a[0];
  m = 1000000;
  for (i = 1; i < n; i++) dp1[i] = dp1[i - 1] + a[i];
  temp = a[n - 1] - dp1[n - 2];
  m = temp;
  cout << m + 1 << endl;
  return 0;
}
