#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[168] = {2,   3,   5,   7,   11,  13,  17,  19,  23,  29,  31,  37,  41,
                43,  47,  53,  59,  61,  67,  71,  73,  79,  83,  89,  97,  101,
                103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167,
                173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239,
                241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313,
                317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397,
                401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467,
                479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569,
                571, 577, 587, 593, 599, 601, 607, 613, 617, 619, 631, 641, 643,
                647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733,
                739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823,
                827, 829, 839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911,
                919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997};
  vector<int> b;
  for (int i = 0; i <= 167; i++) {
    if (a[i] <= n) {
      int y = a[i];
      while (y <= n) {
        b.push_back(y);
        y *= a[i];
      }
    }
  }
  cout << b.size() << endl;
  for (int i = 0; i < b.size(); i++) {
    cout << b[i] << " ";
  }
  return 0;
}
