Problem:
Score : 300 points

Problem Statement

A sequence a_1,a_2,... ,a_n is said to be /\/\/\/ when the following conditions are satisfied:

For each i = 1,2,..., n-2, a_i = a_{i+2}.

Exactly two different numbers appear in the sequence.

You are given a sequence v_1,v_2,...,v_n whose length is even.
We would like to make this sequence /\/\/\/ by replacing some of its elements.
Find the minimum number of elements that needs to be replaced.

Constraints

2 \leq n \leq 10^5

n is even.

1 \leq v_i \leq 10^5

v_i is an integer.

Input

Input is given from Standard Input in the following format:

n
v_1 v_2 ... v_n

Output

Print the minimum number of elements that needs to be replaced.

Sample Input 1

4
3 1 3 2

Sample Output 1

1

The sequence 3,1,3,2 is not /\/\/\/, but we can make it /\/\/\/ by replacing one of its elements: for example, replace the fourth element to make it 3,1,3,1.

Sample Input 2

6
105 119 105 119 105 119

Sample Output 2

0

The sequence 105,119,105,119,105,119 is /\/\/\/.

Sample Input 3

4
1 1 1 1

Sample Output 3

2

The elements of the sequence 1,1,1,1 are all the same, so it is not /\/\/\/.

Solution in Kotlin (1.0.0) (judge verdict: Wrong Answer)

fun c111(args: Array<String>) {
    val numList = args[1].split(" ").map { it.toInt() }
    val firstList = numList.filterIndexed { index, num -> index % 2 == 0 }
    val secondList = numList.filterIndexed { index, num -> index % 2 == 1 }

    var firstMap = mutableMapOf<Int, Int>()
    var firstMostCommonCount = 0
    var firstSecondMostCommonCount = 0
    var firstMostCommonNum = 0
    firstList.forEach {
        if (!firstMap.containsKey(it)) {
            firstMap.put(it, 0)
        }
        firstMap.put(it, firstMap[it]!! + 1)
        if (firstMostCommonCount < firstMap.get(it)!!) {
            firstSecondMostCommonCount = firstMostCommonCount
            firstMostCommonCount = firstMap.get(it)!!
            firstMostCommonNum = it
        }
    }

    var secondMap = mutableMapOf<Int, Int>()
    var secondMostCommonCount = 0
    var secondSecondMostCommonCount = 0
    var secondMostCommonNum = 0
    secondList.forEach {
        if (!secondMap.containsKey(it)) {
            secondMap.put(it, 0)
        }
        secondMap.put(it, secondMap[it]!! + 1)
        if (secondMostCommonCount < secondMap.get(it)!!) {
            secondSecondMostCommonCount = secondMostCommonCount
            secondMostCommonCount = secondMap.get(it)!!
            secondMostCommonNum = it
        }
    }

    if (firstMostCommonNum != secondMostCommonNum) {
        println((firstList.size - firstMostCommonCount) + (secondList.size - secondMostCommonCount))
    } else {
        println(Math.min(
                (firstList.size - firstSecondMostCommonCount) + (secondList.size - secondMostCommonCount),
                (firstList.size - firstMostCommonCount) + (secondList.size - secondSecondMostCommonCount)))

    }
}


fun main(args: Array<String>) {
    c111(readLineList())
}

fun readLineList(): Array<String> {
    val lineList = mutableListOf<String>()
    while (true) {
        val line = readLine()
        if (line.isNullOrBlank()) {
            break
        } else {
            lineList.add(line!!)
        }
    }
    return lineList.toTypedArray()
}