BOJ_24498.java

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
    private void solution() throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());
        int[] arr = new int[n];
        StringTokenizer st = new StringTokenizer(br.readLine());
        for (int i = 0; i < n; i++) arr[i] = Integer.parseInt(st.nextToken());
        int answer = Math.max(arr[0], arr[n-1]);
        for (int i = 1; i < n-1; i++) answer = Math.max(answer, arr[i] + Math.min(arr[i-1], arr[i+1]));
        System.out.println(answer);
    }

    public static void main(String[] args) throws Exception {
        new Main().solution();
    }
}