#include <iostream>

using namespace std;

int main() {
  int data[150000] = {};
  int size = sizeof(data) / sizeof(int);

  for (int i = 2; i < size; ++i) {
    for (int j = i * 2; j < size; j += i)
      data[j] = 1;
  }

  while (true) {
    int n;
    cin >> n;
    if (n == 0)
      break;

    int ans = 0;
    for (int i = 2, cnt = 0; cnt < n; ++i) {
      if (data[i] == 0) {
        ans += i;
        ++cnt;
      }
    }

    cout << ans << endl;
  }
}
