#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0;
  char ch = getchar();
  bool positive = 1;
  for (; ch < '0' || ch > '9'; ch = getchar())
    if (ch == '-') positive = 0;
  for (; ch >= '0' && ch <= '9'; ch = getchar()) x = x * 10 + ch - '0';
  return positive ? x : -x;
}
inline char RC() {
  char c = getchar();
  while (c == ' ' || c == '\n') c = getchar();
  return c;
}
inline long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
inline long long lcm(long long a, long long b, long long MOD) {
  return a / gcd(a, b) * b % MOD;
}
inline long long Sub(long long x, long long y, long long mod) {
  long long res = x - y;
  while (res < 0) res += mod;
  return res;
}
inline long long Add(long long x, long long y, long long mod) {
  long long res = x + y;
  while (res >= mod) res -= mod;
  return res;
}
inline long long POW_MOD(long long x, long long y, long long mod) {
  long long ret = 1;
  while (y > 0) {
    if (y & 1) ret = ret * x % mod;
    x = x * x % mod;
    y >>= 1;
  }
  return ret;
}
const int N = 1005;
const long long INF = 1LL << 62;
const double PI = 3.14159265358;
int n;
vector<int> v;
int main() {
  cin >> n;
  for (int i = 0; i < n; ++i) {
    int tmp;
    cin >> tmp;
    v.push_back(tmp);
  }
  sort(v.begin(), v.end());
  long long sum = 0;
  for (int i = 0; i < n - 1; ++i) {
    sum += v[i];
  }
  cout << abs(v[n - 1] - sum) + 1 << endl;
  return 0;
}
