void main() {
	auto n = ri;
	auto v = readAs!(int[]);
	int[] a, b;
	int[int] c, d;
	foreach(i, e; v) {
		if(i & 1) {
			b ~= e;
			d[e]++;
		} else {
			a ~= e;
			c[e]++;
		}
	}
	if(c != d) {
		auto t = a.length - c.values.reduce!max;
		auto u = b.length - d.values.reduce!max;
		writeln(t + u);
	} else {
		writeln(n/2);
	}
	/*
	writeln(a, b, c, d);
	writeln(a.length - c.values.reduce!max);
	writeln(b.length - d.values.reduce!max);
	*/
}

// ===================================

import std.stdio;
import std.string;
import std.functional;
import std.algorithm;
import std.range;
import std.traits;
import std.math;
import std.container;
import std.bigint;
import std.numeric;
import std.conv;
import std.typecons;
import std.uni;
import std.ascii;
import std.bitmanip;
import core.bitop;

T readAs(T)() if (isBasicType!T) {
	return readln.chomp.to!T;
}
T readAs(T)() if (isArray!T) {
	return readln.split.to!T;
}

T[][] readMatrix(T)(uint height, uint width) if (!isSomeChar!T) {
	auto res = new T[][](height, width);
	foreach(i; 0..height) {
		res[i] = readAs!(T[]);
	}
	return res;
}

T[][] readMatrix(T)(uint height, uint width) if (isSomeChar!T) {
	auto res = new T[][](height, width);
	foreach(i; 0..height) {
		auto s = rs;
		foreach(j; 0..width) res[i][j] = s[j].to!T;
	}
	return res;
}

int ri() {
	return readAs!int;
}

double rd() {
	return readAs!double;
}

string rs() {
	return readln.chomp;
}