#include <bits/stdc++.h>
using namespace std;
const unsigned _mod = 998244353;
unsigned mod;
const long long infi = 0x3f3f3f3f3f3f3f3fll;
const int inf = 0x3f3f3f3f;
long long read() {
  long long x = 0, f = 1;
  char ch = getchar();
  while (ch > '9' || ch < '0') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
long long qpow(long long x, long long y) {
  long long ret = 1;
  while (y) {
    if (y & 1ll) ret = ret * x;
    y >>= 1ll;
    x = x * x;
  }
  return ret;
}
long long ksm(long long x, long long y) {
  long long ret = 1;
  while (y) {
    if (y & 1ll) ret = ret * x % mod;
    y >>= 1ll;
    x = x * x % mod;
  }
  return ret;
}
long long _gcd(long long x, long long y) { return y ? _gcd(y, x % y) : x; }
int a[1000010], n, p[1000010], vis[1000010], cnt, x, f[1000010], num, ans = 1;
int main() {
  cin >> n;
  for (int i = 2; i <= n; ++i) {
    if (!vis[i]) p[++cnt] = i;
    for (int j = 1; j <= cnt; ++j) {
      if (i * p[j] > n) break;
      vis[i * p[j]] = 1;
      if (!(i % p[j])) break;
    }
  }
  for (int i = 1; i <= min(cnt, 66); ++i) {
    cout << "B " << p[i] << endl;
    cin >> x;
    cout << "A " << p[i] << endl;
    cin >> x;
    int tmp = p[i];
    while (x == 1) {
      tmp *= p[i];
      f[++num] = p[i];
      if (tmp > n) break;
      cout << "B " << tmp << endl;
      cin >> x;
      cout << "A " << tmp << endl;
      cin >> x;
    }
  }
  if (num)
    for (int i = 1; i <= num; ++i) ans *= f[i];
  if (ans != 1)
    for (int i = 67; i <= cnt; ++i) {
      cout << "A " << p[i] << endl;
      cin >> x;
      if (x != 1) return cout << "C " << ans * p[i] << endl, 0;
    }
  if (ans != 1) return cout << "C " << ans << endl, 0;
  cout << "A 1" << endl;
  cin >> x;
  int tot = x, k = 0;
  for (int i = 67; i <= cnt; ++i) {
    cout << "B " << p[i] << endl;
    cin >> x;
    k++;
    if (!(k % 100) || i == cnt) {
      cout << "A 1" << endl;
      cin >> x;
      if (x == tot - k)
        tot = x, k = 0;
      else
        for (int j = i - k + 1; j <= i; ++j) {
          cout << "A " << p[j] << endl;
          cin >> x;
          if (x == 1) return cout << "C " << p[j] << endl, 0;
        }
    }
  }
  cout << "C " << ans << endl;
  return 0;
}
