#include <bits/stdc++.h>
using namespace std;
const int oo = 1e9 + 5;
const long long int ooll = (long long int)1e18 + 5;
const int MOD = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
clock_t start = clock();
const int N = (int)1e5 + 1;
const int BLOCK = 98;
int v[N], sp[N], pres[N], n, tot, gone[N];
bool debug = false;
int judge_a[N], x, MX_QUERIES = 9999, Q = 0;
int ask(int a, char type) {
  ++Q;
  assert(Q <= MX_QUERIES);
  if (debug) {
    int got = 0;
    for (int j = a; j <= n; j += a) {
      if (judge_a[j] == 1) ++got;
      if (type == 'B' && j != x) judge_a[j] = 0;
    }
    return got;
  }
  cout << type << " " << a << '\n';
  fflush(stdout);
  if (type == 'B') {
    for (int j = a; j <= n; j += a) {
      if (gone[j] == 1) {
        tot--;
      }
      gone[j] = 0;
    }
  }
  int ans;
  cin >> ans;
  return ans;
}
void pre() {
  for (int i = 1; i <= N; ++i) sp[i] = i;
  for (int i = 2; i < N; ++i)
    if (sp[i] == i) {
      if (i * 1LL * i >= N) break;
      for (int j = i + i; j < N; j += i) sp[j] = min(sp[j], i);
    }
}
void solve() {
  vector<int> primes;
  cin >> n;
  Q = 0;
  if (debug) cin >> x;
  tot = n;
  for (int i = 0; i <= n; ++i) {
    pres[i] = 0;
    judge_a[i] = 1;
    gone[i] = 1;
  }
  for (int i = 2; i <= n; ++i) {
    if (sp[i] == i) primes.push_back(i);
    pres[sp[i]]++;
  }
  vector<int> have;
  int psz = primes.size(), sj = psz - 1, nb = (psz - 1) % BLOCK;
  bool found = false;
  for (int j = 0; j < psz; ++j) {
    int it = primes[j];
    int go = ask(it, 'B');
    if (go != pres[it]) {
      have.push_back(it);
    }
    if (j % BLOCK == nb && !found) {
      int go = ask(1, 'A');
      if (go != tot) {
        sj = j;
        found = true;
      }
    }
  }
  if (!have.empty()) {
    for (int j = 0; j < psz; ++j) {
      int it = primes[j];
      if (it * 1LL * it >= n) break;
      int go = ask(it, 'A');
      if (go > 0) {
        have.push_back(it);
        break;
      }
    }
    int ans = 1;
    for (auto it : have) {
      int pw = it;
      assert(it > 1);
      while (pw * 1LL * it <= n) {
        pw *= it;
        int go = ask(pw, 'A');
        if (go == 0) {
          pw /= it;
          break;
        }
      }
      ans *= pw;
    }
    if (debug) {
      assert(x == ans);
    } else {
      cout << "C " << ans << '\n';
      fflush(stdout);
    }
    return;
  }
  int l = max(0, sj - BLOCK + 1), r = sj;
  for (int j = l; j <= r; ++j) {
    int go = ask(primes[j], 'A');
    if (go > 0) {
      int pw = primes[j];
      while (pw * 1LL * primes[j] <= n) {
        pw *= primes[j];
        int go = ask(pw, 'A');
        if (go == 0) {
          pw /= primes[j];
          break;
        }
      }
      int ans = pw;
      if (debug) {
        assert(x == ans);
      } else {
        cout << "C " << ans << '\n';
        fflush(stdout);
      }
      return;
    }
  }
  if (debug) {
    assert(x == 1);
  } else {
    cout << "C 1\n";
    fflush(stdout);
  }
}
int main() {
  int T = 1;
  pre();
  for (int t = 1; t <= T; ++t) {
    solve();
  }
  return 0;
}
