import java.util.*;
import java.lang.*;
import java.io.*;

// The main method must be in a class named "Main".
public class Main {
    public static void increasingDecreasing(int i, int n) {
        if (i == n + 1)
            return;
        System.out.print(i + " ");
        increasingDecreasing(i + 1, n);
        System.out.print(i + " ");
    }

    public static void main(String[] args) {
        int n = 4; // Change n to any desired value
        increasingDecreasing(1, n);
    }
}