#include <bits/stdc++.h>
using namespace std;
int a[1000001];
int main() {
  int n, k;
  cin >> n >> k;
  if (k == 1) return puts("3"), 0;
  for (int i = 1; i <= n; i++) a[i] = i;
  for (int i = 2; i <= n; i++)
    if (a[i] == i) {
      for (int j = i; j <= n; j += i) a[j] = (a[j] / i) * (i - 1);
    }
  sort(a + 3, a + n + 1);
  cout << accumulate(a + 3, a + k + 3, 0ll) + 2 << endl;
  return 0;
}
