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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

(function(input) {
  'use strict';
  const INPUT = input.split("\n")
  for(let i = 0; i<INPUT.length; i=i+2){
    if(!INPUT[i] || !INPUT[i+1]) continue
    if (INPUT[i] === 2) {
      console.log('0')
      continue
    }
    const length = INPUT[i]
    const line = INPUT[i+1].split(" ")
    let Max = 0
    let MaxNumFirst = ''
    let countHashFirst = {}
    for(let j=0; j< length; j=j+2){
      countHashFirst[line[j]]
      ? countHashFirst[line[j]]++
      : countHashFirst[line[j]]=1
      if(countHashFirst[line[j]] > Max){
        Max = countHashFirst[line[j]]
        MaxNumFirst = line[j]
      }
    }

    Max = 0
    let MaxNumSencond = ''
    let countHashSecond = {}
    for(let j=1; j< length; j=j+2){
      countHashSecond[line[j]]
      ? countHashSecond[line[j]]++
      : countHashSecond[line[j]]=1
      if(countHashSecond[line[j]] > Max){
        Max = countHashSecond[line[j]]
        MaxNumSencond = line[j]
      }
    }
 
    let res = 0
    for(let j=0; j< length; j=j+2){
      if(MaxNumFirst != line[j]) res++
      if(MaxNumSencond != line[j+1]) res++
    }

    console.log(res)
  }
})(require('fs').readFileSync('/dev/stdin', 'utf8'))