#include<iostream>
#include<cstdio>
#define N 100000
using namespace std;
int read()
{
	char c=0;
	int sum=0;
	while (c<'0'||c>'9') c=getchar();
	while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
	return sum;
}
int n,sz,limit=1,a[N+1],p[N+1];
bool used[N+1];
void solve(int x)
{
	if (x==1)
	{
		p[0]=0;
		return;
	}
	if (x==2)
	{
		p[0]=1,p[1]=0;
		return;
	}
	if (x==8)
	{
		p[0]=1,p[1]=0,p[2]=2,p[3]=4,p[4]=3,p[5]=6,p[6]=5,p[7]=7;
		return;
	}
	solve(x>>1);
	for (int i=(x>>1);i<x;++i) p[i]=p[(i-(x>>1)+1)%(x>>1)]+(x>>1);
	return;
}
void dfs(int x,int d)
{
	if (x==sz+1)
	{
		printf("%d\n",sz);
		for (int i=1;i<=sz;++i) printf("%d ",a[i]);
		puts("");
		exit(0);
		return;
	}
	bool op;
	for (int i=d;i<=n-(sz-x);++i)
	{
		op=1;
		for (int j=1;j<=x-1;++j) op&=(!used[a[j]^i]);
		if (op)
		{
			for (int j=1;j<=x-1;++j) used[a[j]^i]=1;
			a[x]=i,dfs(x+1,i+1);
			for (int j=1;j<=x-1;++j) used[a[j]^i]=0;
		}
	}
	return;
}
int main()
{
	n=read();
	while ((((sz+1)*(sz+1))<<1)<=n) sz++;
	if (n<=63) dfs(1,1);
	else
	{
		while (limit<sz||limit==4) limit<<=1;
		solve(limit);
		printf("%d\n",limit);
		for (int i=0;i<limit;++i) printf("%d ",p[i]*limit|i);
		puts("");
	}
	return 0;
}