Math professor of your brother has given a homework. He has given a series of numbers. And, he is asking the sum of (min of odd positions) and (max of even positions).

Question: Write a program that is going to read n numbers and show the result.

Input specification
In the first line, you will be an integer, the number of numbers (n) where 0 ≤ n ≤ 40,000. Then, in the following n lines, you will be given n integers where the numbers are between -1e8 and +1e8
Note: The number positions goes from 1 to n.

Output specification:
Show the sum of the minimum of odd positions and the maximum of even positions.

Explanation: There are 3 numbers in odd positions: 14, 17 and 85. And, the min of odd positions is 14. The max of even positions is 30. So, the sum is 44.