#include <bits/stdc++.h>
using namespace std;
long long n;
bool isp[100005] = {0};
vector<long long> pr;
int main(void) {
  scanf("%lld", &n);
  for (long long i = 2; i <= n; i++) {
    if (isp[i] == 0) {
      pr.push_back(i);
      for (long long j = i * i; j <= n; j += i) isp[j] = 1;
    }
  }
  for (long long i = 1; i <= n; i++) isp[i] = 1;
  long long x;
  if (n <= 10) {
    for (long long i = n; i >= 2; i--) {
      printf("B %lld\n", i);
      fflush(stdout);
      scanf("%lld", &x);
      printf("A %lld\n", i);
      fflush(stdout);
      scanf("%lld", &x);
      if (x == 1) {
        printf("C %lld\n", i);
        fflush(stdout);
        return 0;
      }
    }
    printf("C 1\n");
    fflush(stdout);
    return 0;
  }
  long long siz = 90;
  long long now = n;
  long long ans = 1;
  for (long long i = 1; i * siz < pr.size(); i++) {
    long long upp = min((long long)pr.size(), (i + 1) * siz);
    for (long long j = i * siz; j < upp; j++) {
      printf("B %lld\n", pr[j]);
      fflush(stdout);
      scanf("%lld", &x);
      for (long long k = pr[j]; k <= n; k += pr[j]) {
        if (isp[k] == 1) isp[k] = 0, now--;
      }
    }
    printf("A 1\n");
    fflush(stdout);
    scanf("%lld", &x);
    if (x != now) {
      for (long long j = i * siz; j < upp; j++) {
        printf("A %lld\n", pr[j]);
        fflush(stdout);
        scanf("%lld", &x);
        long long no1 = pr[j];
        while (x != 0) {
          ans *= pr[j];
          no1 *= pr[j];
          if (no1 > n) break;
          ;
          printf("A %lld\n", no1);
          fflush(stdout);
          scanf("%lld", &x);
          if (x == 0) break;
        }
      }
      break;
    }
  }
  for (long long j = 0; j < min((long long)pr.size(), siz); j++) {
    printf("B %lld\n", pr[j]);
    fflush(stdout);
    scanf("%lld", &x);
    printf("A %lld\n", pr[j]);
    fflush(stdout);
    scanf("%lld", &x);
    long long no1 = pr[j];
    while (x != 0) {
      ans *= pr[j];
      no1 *= pr[j];
      if (no1 > n) break;
      ;
      printf("A %lld\n", no1);
      fflush(stdout);
      scanf("%lld", &x);
      if (x == 0) break;
    }
  }
  printf("C %lld\n", ans);
  fflush(stdout);
}
