#include <bits/stdc++.h>   using namespace std;   int main() {     int n, i, j;     scanf( %d , &n);     if (n == 1)       printf( 1 n1 n );     else if (n == 2)       printf( 1 n1 n );     else if (n == 3)       printf( 2 n1 3 n );     else if (n == 4)       printf( 4 n2 4 1 3 n );     else {       printf( %d n , n);       for (j = 2; j <= n; j += 2) printf( %d  , j);       for (j = 1; j <= n; j += 2) printf( %d  , j);     }     return 0;   }   