#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const int maxn = 1e5 + 100;
const long long linf = 9223372036854775807;
const int inf = 1 << 31;
const double eps = 1e-4;
const double DoubleInf = 1e20;
const double pi = acos(-1.0);
long long qpow(long long a, long long b) {
  return b ? ((b & 1) ? a * qpow(a * a % MOD, b >> 1) % MOD
                      : qpow(a * a % MOD, b >> 1)) %
                 MOD
           : 1ll;
}
long long quick_mod(long long a, long long b, long long MOD) {
  long long ans = 1;
  a %= MOD;
  while (b) {
    if (b & 1) {
      ans = ans * a % MOD;
      b--;
    }
    b >>= 1;
    a = a * a % MOD;
  }
  return ans;
}
inline int ird() {
  register int x = 0, f = 1;
  register char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9')
    x = (x << 3) + (x * 2) + ch - '0', ch = getchar();
  return x * f;
}
inline long long lrd() {
  register long long x = 0, f = 1;
  register char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9')
    x = (x << 3) + (x * 2) + ch - '0', ch = getchar();
  return x * f;
}
void puts1() { cout << "-1" << endl; }
void puts2() { cout << "YES" << endl; }
void puts3() { cout << "NO" << endl; }
int gcd(int a, int b) { return (b > 0) ? gcd(b, a % b) : a; }
int lcm(int a, int b) { return a * b / gcd(a, b); }
long long lgcd(long long a, long long b) {
  return (b > 0) ? lgcd(b, a % b) : a;
}
long long llcm(long long a, long long b) { return a * b / lgcd(a, b); }
int v[maxn], prime[maxn];
int primes(int n) {
  int m = 0;
  for (int i = 2; i <= n; i++) {
    if (v[i] == 0) {
      v[i] = i;
      prime[++m] = i;
    }
    for (int j = 1; j <= m; j++) {
      if (prime[j] > v[i] || prime[j] > n / i) break;
      v[i * prime[j]] = prime[j];
    }
  }
  return m;
}
int main() {
  int n, m, ans, M, g, start;
  int t;
  int tt, tot, temp, cur;
  tot = 0;
  cur = 0;
  g = 0;
  start = 0;
  M = primes(maxn);
  ans = 1;
  scanf("%d", &n);
  if (n == 1) {
    printf("C 1\n");
    return 0;
  }
  for (int i = 1; prime[i] <= n; i++) {
    cur++;
    if ((long long)(prime[i]) * (long long)(prime[i]) > (long long)(n))
      g++;
    else
      start = i;
  }
  M = cur;
  for (int i = 1; prime[i] * prime[i] <= n; i++) {
    cur--;
    printf("B %d\n", prime[i]);
    fflush(stdout);
    scanf("%d", &tt);
    printf("A %d\n", prime[i]);
    fflush(stdout);
    scanf("%d", &tt);
    if (tt) {
      ans *= prime[i];
      temp = prime[i];
      while (temp * prime[i] <= n) {
        temp *= prime[i];
        printf("A %d\n", temp);
        fflush(stdout);
        scanf("%d", &tt);
        if (tt == 0)
          break;
        else
          ans *= prime[i];
      }
    }
  }
  int s = (int)(sqrt(g));
  int pos;
  if (ans == 1) {
    for (int i = 0; i <= g / s - (g % s == 0); i++) {
      if (ans != 1) break;
      for (int j = 0; j < s; j++) {
        pos = start + i * s + j + 1;
        if (pos > M) continue;
        printf("B %d\n", prime[pos]);
        fflush(stdout);
        scanf("%d", &tt);
        cur--;
      }
      printf("A 1\n");
      fflush(stdout);
      scanf("%d", &tt);
      if (tt != cur + 1) {
        for (int j = 0; j < s; j++) {
          pos = start + i * s + j + 1;
          if (pos > M) continue;
          printf("A %d\n", prime[pos]);
          fflush(stdout);
          scanf("%d", &tt);
          if (tt) {
            ans *= prime[pos];
          }
        }
      }
    }
  } else {
    for (int i = start + 1; prime[i] <= n; i++) {
      printf("A %d\n", prime[i]);
      fflush(stdout);
      scanf("%d", &tt);
      if (tt == 2) {
        ans *= prime[i];
        break;
      }
    }
  }
  printf("C %d\n", ans);
  return 0;
}
