import std.stdio, std.conv, std.string, std.array, std.range, std.algorithm, std.container;
import std.math, std.random, std.bigint, std.datetime, std.format;
void main(string[] args){ if(args.length > 1) if(args[1] == "-debug") DEBUG = 1; solve(); }
void log()(){ writeln(""); } void log(T, A ...)(T t, lazy A a){ if(DEBUG) write(t, " "), log(a); } bool DEBUG = 0; 
string read(){ static string[] ss; while(!ss.length) ss = readln.chomp.split; string res = ss[0]; ss.popFront; return res; }
// ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- //

void solve(){
	int n = read.to!int;
	int k = read.to!int;
	
	int[] as;
	foreach(i; 0 .. n) as ~= read.to!int;
	
	int[int] ac;
	foreach(a; as){
		if(a !in ac) ac[a] = 0;
		ac[a] += 1;
	}
	
	int ans;
	int ocnt = n % 2;
	int[] ks = ac.keys;
	foreach(a; ks){
		int c = ac[a];
		if(c % 2 == 0) ans += c;
		else{
			if(ocnt >= 1) ans += c, ocnt = 0;
			else ans += c - 1, ocnt = 1;
		}
		log("a:", a, "cnt:", c, "ocnt:", ocnt, "ans:", ans);
	}
	
	ans.writeln;
}
