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 Main(input) {
  input = input.split("\n");
  n = parseInt(input[0]);
  tmp=input[1].split(" ");
  v=new Array(n);
  var countse = {};
  var countso = {};
  var maxe1 =0;
  var maxe2 =0;
  var maxenum=0;
  var maxo1 =0;
  var maxo2 =0;
  var maxonum=1;
  var ans =0;
  for(i=0;i<n;i++){
    v[i]=parseInt(tmp[i]);
    if(i%2==0){
      var num = v[i];
      countse[num]=countse[num] ? countse[num] +1 :1;
      if(maxe1!=0&&v[maxenum]!=v[i]&&countse[num]>maxe2){
        maxe2=countse[num];
      }
      if(countse[num]>maxe1){
        if(v[maxenum]!=v[i]){
          maxe2=maxe1;
        }
        maxe1=countse[num];
        maxenum=i;
      }
    }else{
      var num = v[i];
      countso[num]=countso[num] ? countso[num] +1: 1;
      if(maxo1!=0&&v[maxonum]!=v[i]&&countso[num]>maxo2){
        maxo2=countso[num];
      }
      if(countso[num]>maxo1){
        if(v[maxonum]!=v[i]){
          maxo2=maxo1;
        }
        maxo1=countso[num];
        maxonum=i
      }
    }
  }

  if(v[maxenum]!=v[maxonum]){
    ans=n-maxe1-maxo1;
  }else{
    if((Math.ceil(n/2)-maxe1)<(Math.floor(n/2)-maxo1)){
      ans=n-maxe2-maxo1;
    }else{
      ans=n-maxe1-maxo2;
    }
  }


  console.log('%s', ans);
}
  
// "実行する"ボタンを押した時に実行される関数 (デバッグ用)
function debug(){
  var input = document.getElementById("input").value;
  Main(input);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));