P25786 [AtCoder] Takahashi and Animals
普及+
题目描述

Problem Statement

Takahashi is with N animals.
The N animals are called Animal $1, Animal 2, \ldots, Animal N$.
Takahashi will perform the following N kinds of action. Each action can be performed any number of (possibly zero) times.

  • Pay A_1 yen (the currency in Japan) to feed Animals 1 and 2.
  • Pay A_2 yen to feed Animals 2 and 3.
  • Pay A_3 yen to feed Animals 3 and 4.
  • $\cdots$
  • Pay A_i yen to feed Animals i and (i+1).
  • $\cdots$
  • Pay A_{N-2} yen to feed Animals (N-2) and (N-1).
  • Pay A_{N-1} yen to feed Animals (N-1) and N.
  • Pay A_N yen to feed Animals N and 1.

Note that the N-th action above feeds "Animals N and 1."
Print the minimum possible total cost to feed every animal at least once.

Input

Input is given from Standard Input in the following format:
N
$A_1 A_2 \ldots A_N$

Output

Print the minimum possible total cost to feed every animal at least once.

Constraints

  • $2 \leq N \leq 3 \times 10^5$
  • $1 \leq A_i \leq 10^9$
  • All values in input are integers.

Sample Input 1

5
2 5 3 2 5

Sample Output 1

7

If Takahashi performs the 1-st, 3-rd, and 4-th actions once each, Animals 1, 2, 3, 4, and 5 are fed once, once, once, twice, once, respectively, so every animal is fed at least once.
The total cost to do so is A_1 + A_3 + A_4 = 2 + 3 + 2 = 7 yen, which is the minimum possible.

Sample Input 2

20
29 27 79 27 30 4 93 89 44 88 70 75 96 3 78 39 97 12 53 62

Sample Output 2

426

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
5 2 5 3 2 5
样例输出
7