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 MaxPair = ''
    let countHash = {}
    for(let j=0; j< length; j=j+2){
      countHash[[line[j],line[j+1]].toString()]
      ? countHash[[line[j],line[j+1]].toString()]++
      : countHash[[line[j],line[j+1]].toString()]=1
      if(countHash[[line[j],line[j+1]].toString()] > Max){
        Max = countHash[[line[j],line[j+1]].toString()]
        MaxPair = [line[j],line[j+1]].toString()
      }
    }

    MaxPair = MaxPair.split(',')
    let res = 0
    for(let j=0; j< length; j=j+2){
      if(MaxPair[0] != line[j]) res++
      if(MaxPair[1] != line[j+1]) res++
    }
    console.log(res)
  }
})(require('fs').readFileSync('/dev/stdin', 'utf8'))