#include <bits/stdc++.h>
using namespace std;
int main(int argc, char** argv) {
  int rods[100000];
  int n;
  cin >> n;
  int maxi = 0;
  for (int i = 0; i < n; i++) {
    cin >> rods[i];
    maxi = maxi >= rods[i] ? maxi : rods[i];
  }
  int total = maxi;
  for (int i = 0; i < n; i++) {
    if (rods[i] == maxi)
      continue;
    else
      total -= rods[i];
  }
  cout << 1 + total << endl;
  return 0;
}
