package main

import "fmt"

func main() {
    var n int
    fmt.Scan(&n)
    m := 2 * n
    arr := make([]int, m+1)
    for i := 1; i <= n-1; i++ {
        d := n - i
        for s := 1; s <= m-d; s++ {
            if arr[s] == 0 && arr[s+d] == 0 {
                arr[s] = i
                arr[s+d] = i
                break
            }
        }
    }
    var remains []int
    for p := 1; p <= m; p++ {
        if arr[p] == 0 {
            remains = append(remains, p)
        }
    }
    arr[remains[0]] = n
    arr[remains[1]] = n
    for p := 1; p <= m; p++ {
        if p > 1 {
            fmt.Print(" ")
        }
        fmt.Print(arr[p])
    }
    fmt.Println()
}