#include <bits/stdc++.h>
using namespace std;
const double pi = acos(-1.0);
const double eps = 1e-8;
const int mxn = 100033;
const int mod = 1e9 + 7;
inline int read() {
  int x = 0, f = 1;
  char c = getchar();
  while (!isdigit(c)) f = c == '-' ? -1 : 1, c = getchar();
  while (isdigit(c)) x = x * 10 + c - '0', c = getchar();
  return x * f;
}
inline long long gcd(long long a, long long b) {
  return b == 0 ? a : gcd(b, a % b);
}
long long ksm(long long a, long long b, long long mod) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = (ans * a) % mod;
    a = (a * a) % mod;
    b >>= 1;
  }
  return ans;
}
long long inv2(long long a, long long mod) { return ksm(a, mod - 2, mod); }
void exgcd(long long a, long long b, long long &x, long long &y, long long &d) {
  if (!b) {
    d = a;
    x = 1;
    y = 0;
  } else {
    exgcd(b, a % b, y, x, d);
    y -= x * (a / b);
  }
}
int dx[] = {0, 1, 0, -1};
int dy[] = {1, 0, -1, 0};
int n, prime[mxn];
bool isnp[mxn];
void euler() {
  memset((isnp), (0), sizeof((isnp)));
  isnp[1] = 1;
  for (int i = 2; i <= n; ++i) {
    if (!isnp[i]) prime[++prime[0]] = i;
    for (int j = 1; j <= prime[0] && i * prime[j] <= n; ++j) {
      isnp[i * prime[j]] = 1;
      if (i % prime[j] == 0) break;
    }
  }
}
int x;
long long res = 1;
void query(int opt, int v) {
  if (opt == 1) {
    cout << "A"
         << " " << v << endl;
    cin >> x;
  } else if (opt == 2) {
    cout << "B"
         << " " << v << endl;
    cin >> x;
  } else
    cout << "C"
         << " " << res << endl;
}
void find(int p) {
  while (res * p <= n) {
    query(1, res * p);
    if (x)
      res *= p;
    else
      break;
  }
}
int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  std::cout.tie(0);
  ;
  cin >> n;
  euler();
  int sz = sqrt(prime[0]);
  for (int i = 1, cur = n, sum; i <= prime[0]; i += sz) {
    sum = 0;
    for (int j = 0; i + j <= prime[0] && j < sz; ++j) {
      query(2, prime[i + j]);
      sum += x;
    }
    query(1, 1);
    int tmp = x;
    if (sum > cur - x) {
      for (int j = 0; i + j <= prime[0] && j < sz; ++j) find(prime[i + j]);
    }
    cur = tmp;
  }
  query(3, 0);
  return 0;
}
