#include <bits/stdc++.h>
using namespace std;
const int N = 100005;
int lp[N + 1];
vector<long long> pr;
int main() {
  for (int i = 2; i <= N; ++i) {
    if (lp[i] == 0) {
      lp[i] = i;
      pr.push_back(i);
    }
    for (int j = 0; j < (int)pr.size() && pr[j] <= lp[i] && i * pr[j] <= N; ++j)
      lp[i * pr[j]] = pr[j];
  }
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n;
  cin >> n;
  if (n == 1) {
    cout << "C 1" << endl;
    cout.flush();
    return 0;
  }
  while (pr.back() > n) pr.pop_back();
  vector<long long> factor;
  bool toggle[n + 1];
  memset(toggle, 0, sizeof(toggle));
  int i = 0;
  for (; i + 100 < pr.size(); i += 100) {
    for (int a = 0; a < 100; a++) {
      cout << "B " << pr[i + a] << endl;
      cout.flush();
      int res;
      cin >> res;
      for (int b = pr[i + a]; b <= n; b += pr[i + a]) toggle[b] = true;
    }
    int shouldbe = 0;
    for (int a = 1; a <= n; a++)
      if (!toggle[a]) shouldbe++;
    cout << "A 1" << endl;
    cout.flush();
    int actual;
    cin >> actual;
    if (actual != shouldbe) break;
  }
  for (; i < pr.size(); i++) {
    cout << "B " << pr[i] << endl;
    cout.flush();
    for (int a = pr[i]; a <= n; a += pr[i]) toggle[a] = true;
    int bef;
    cin >> bef;
    cout << "A " << pr[i] << endl;
    cout.flush();
    int ans;
    cin >> ans;
    if (ans != 0) {
      factor.push_back(pr[i]);
      i++;
      break;
    }
  }
  while (i < pr.size()) {
    cout << "B " << pr[i] << endl;
    cout.flush();
    int actual;
    cin >> actual;
    int shouldbe = 0;
    for (int a = pr[i]; a <= n; a += pr[i]) {
      if (!toggle[a]) shouldbe++, toggle[a] = true;
    }
    if (shouldbe != actual) factor.push_back(pr[i]);
    i++;
  }
  long long ans = 1;
  for (int i = 0; i < factor.size(); i++) {
    long long ite = 1;
    while (ite * factor[i] <= n) ite *= factor[i];
    for (; ite > 1; ite /= factor[i]) {
      cout << "A " << ite << endl;
      cout.flush();
      int res;
      cin >> res;
      if (res != 0) {
        ans *= ite;
        break;
      }
    }
  }
  cout << "C " << ans << endl;
}
