#include <bits/stdc++.h>
using namespace std;
int n, tot;
int pri[100005], num[100005];
int vis[100005], lef[100005], vis2[100005];
void init() {
  scanf("%d", &n);
  for (int i = 2; i <= n; i++) {
    if (!vis[i]) {
      pri[++tot] = i, num[i] = tot, lef[i] = 1;
      for (int j = i + i; j <= n; j += i) {
        if (i >= min(320, n) + 1 && vis2[j] == 0) {
          vis2[j] = 1;
          lef[i]++;
        }
        vis[j] = 1;
      }
    }
  }
}
long long ans = 1;
void solvebig() {
  int cnt = 0, pre = 0;
  printf("A %d\n", 1);
  fflush(stdout);
  scanf("%d", &pre);
  for (int i = min(320, n) + 1; i <= n; i++)
    if (!vis[i]) {
      int _;
      printf("B %d\n", i);
      fflush(stdout);
      scanf("%d", &_);
      pre -= lef[i];
      cnt++;
      if (cnt % 50 == 0 || pri[num[i] + 1] == 0) {
        int gg = 0;
        printf("A %d\n", 1);
        fflush(stdout);
        scanf("%d", &gg);
        if (pre != gg) {
          for (int j = i; j >= 1; j--)
            if (!vis[j]) {
              int x;
              printf("A %d\n", j);
              fflush(stdout);
              scanf("%d", &x);
              if (x != 0) {
                ans *= j;
                break;
              }
            }
          return;
        }
      }
    }
}
void solvesmall() {
  for (int i = 2; i <= min(320, n); i++)
    if (!vis[i]) {
      int x;
      printf("B %d\n", i);
      fflush(stdout);
      scanf("%d", &x);
      printf("A %d\n", i);
      fflush(stdout);
      scanf("%d", &x);
      if (x != 0) {
        int temp = i;
        ans *= i;
        for (int j = 2; j <= 100000; j++) {
          temp = temp * i;
          if (temp > n) break;
          printf("A %d\n", temp);
          fflush(stdout);
          scanf("%d", &x);
          if (x == 0)
            break;
          else
            ans = ans * i;
        }
      }
    }
}
void output() {
  printf("C %lld\n", ans);
  fflush(stdout);
}
int main() {
  init();
  solvebig();
  solvesmall();
  output();
  return 0;
}
