A.cpp

#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i=(a),_b=(b); i<=_b; i++)
#define FORD(i,a,b) for(int i=(a),_b=(b); i>=_b; i--)
#define REP(i,a) for(int i=0,_a=(a); i<_a; i++)
#define EACH(it,a) for(__typeof(a.begin()) it = a.begin(); it != a.end(); ++it)

#define DEBUG(x) { cout << #x << " = "; cout << (x) << endl; }
#define PR(a,n) { cout << #a << " = "; FOR(_,1,n) cout << a[_] << ' '; cout << endl; }
#define PR0(a,n) { cout << #a << " = "; REP(_,n) cout << a[_] << ' '; cout << endl; }

#define sqr(x) ((x) * (x))
#define ll long long
using namespace std;

bool isPrime(int n) {
    for(int i = 2; i*i <= n; ++i)
        if (n % i == 0) return false;
    return n > 1;
}

int main() {
    ios :: sync_with_stdio(false);
    int n;
    while (cin >> n) {
        vector<int> res;
        FOR(i,2,n) if (isPrime(i)) {
            int j = i;
            while (j <= n) {
                res.push_back(j);
                j *= i;
            }
        }
        sort(res.begin(), res.end());
        cout << res.size() << '\n';
        for(int x : res) cout << x << ' '; cout << '\n';
    }
}