// Author: wlzhouzhuan
#include<bits/stdc++.h>
using namespace std;

#define rep(i,l,r) for(int i=(l);i<=(r);i++)
#define per(i,l,r) for(int i=(l);i>=(r);i--)
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define mset(s,t) memset(s,t,sizeof(s))
#define mcpy(s,t) memcpy(s,t,sizeof(t))
#define SZ(x) ((int)x.size())
#define pb push_back
#define eb emplace_back
#define fir first
#define sec second

template<class T1,class T2>bool ckmax(T1 &a,T2 b){if(a<b)return a=b,1;else return 0;}
template<class T1,class T2>bool ckmin(T1 &a,T2 b){if(a>b)return a=b,1;else return 0;}

inline int read(){
    int x=0,f=0;char ch=getchar();
    while(!isdigit(ch))f|=ch=='-',ch=getchar();
    while(isdigit(ch))x=10*x+ch-'0',ch=getchar();
    return f?-x:x;
}
template<typename T>void print(T x){
    if(x<0)putchar('-'),x=-x;
    if(x>=10)print(x/10);
    putchar(x%10+'0');
}
template<typename T>void print(T x,char ch){
    print(x),putchar(ch);
}

const int mod=998244353;
const int inv2=(mod+1)/2;

inline int qpow(int a,int b=mod-2){
    int res=1;
    while(b>0){
        if(b&1)res=1ll*res*a%mod;
        a=1ll*a*a%mod,b>>=1;
    }
    return res;
}
inline int fac(int x,int y){
    int ans=1;
    per(i,x,y+1)ans=1ll*ans*i%mod;
    return ans;
}

const int N=3000005;

ll a[N],len;
ll n;

void solve(){
    len=0;
    a[++len]=1,a[++len]=2;
    for(ll i=3;;i++){
        while(__gcd(i,a[len-1])!=1)i++;
        a[++len]=i;
        if(a[len]*a[len-1]>n)break;
    }

    vector<ll>ans;
    ans.pb(1);
    for(int i=1;i<len;i++){
        if(a[i]*a[i+1]>n)break;
        ans.pb(a[i]*a[i+1]);
    }
    ll least=ceil(sqrt(n)*2./3);
    // printf("least=%lld\n",least);
    // if(least>SZ(ans)){
    //     // printf("%d\n",n);
    //     // return;
    //     if(n==2||n==3)puts("2\n1 3");
    //     else{
    //         assert(n>=21&&n<=24);
    //         puts("4\n1 2 6 15");// n=21,22,23,24
    //     }
    //     return;
    // }
    assert(least<=SZ(ans));
    printf("%d\n",SZ(ans));
    for(auto v:ans){
        printf("%lld ",v);
    }
    puts("");
}

int main(){
    cin>>n;solve();
    // while(n<=100000){
    //     ++n;
    //     solve();
    //     if(n%10000==0)printf("finished %lld\n",n);
    // }
    return 0;
}