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