#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <chrono>
#define _USE_MATH_DEFINES
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <deque>
#include <functional>
#include <iostream>
#include <iterator>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;

#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3fLL;
const double EPS = 1e-8;
const int MOD = 1000000007; // 998244353;
const int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
/*-------------------------------------------------*/
int main() {
  cin.tie(0); ios::sync_with_stdio(false);
  // freopen("input.txt", "r", stdin);

  string s; getline(cin, s);
  int n = stoi(s);
  getline(cin, s);
  int pos = s.find(' ');
  if (pos == s.npos) {
    vector<long long> a(3);
    a[0] = stoll(s);
    FOR(i, 1, 3) cin >> a[i];
    vector<long long> tmp;
    REP(i, 3) FOR(j, i + 1, 3) tmp.emplace_back(a[i] + a[j]);
    sort(ALL(tmp));
    tmp.erase(unique(ALL(tmp)), tmp.end());
    reverse(ALL(tmp));
    cout << tmp[1] << '\n';
  } else {
    cout << "\"assert\"\n";
  }
  return 0;
}