#include <bits/stdc++.h>

using namespace std;

#define ll long long int
#define nl endl
#define ss string
#define dl double
#define yes cout << "YES" << nl;
#define no cout << "NO" << nl;


int main() {
    ll t; cin >> t;
    for (int i = 1; i <= t; i++)
    {
        /* code */
 
    if(i % 2 == 0)
    {
        cout << i << nl;
        break;
    }
    }
   
    
    return 0;
}