#include <bits/stdc++.h>
using namespace std;
int main(){
	int n; cin>>n;
	cout<<(1<<n)-1<<endl;
	for(int i=1;i<1<<n;i++){
		for(int j=0;j<1<<n;j++){
			if(__builtin_popcount(j&i)&1) cout<<'B';
			else cout<<'A';
		}
		cout<<endl;
	}
}

#include <bits/stdc++.h>
using namespace std;
using lint = long long int;
using P = pair<int, int>;
using PL = pair<lint, lint>;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
#define ALL(a)  (a).begin(),(a).end()
constexpr int MOD = 1000000007;
constexpr lint B1 = 1532834020;
constexpr lint M1 = 2147482409;
constexpr lint B2 = 1388622299;
constexpr lint M2 = 2147478017;
constexpr int INF = 2147483647;
void yes(bool expr) {cout << (expr ? "Yes" : "No") << "\n";}
template<class T>void chmax(T &a, const T &b) { if (a<b) a=b; }
template<class T>void chmin(T &a, const T &b) { if (b<a) a=b; }
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int N;
  cin >> N;
  vector<string> now;
  now.push_back("AB");
  N--;
  int len = 2;
  while(N--) {
    vector<string> next;
    string tmp = "";
    REP(i, len) tmp += 'A';
    REP(i, len) tmp += 'B';
    next.push_back(tmp);
    REP(i, now.size() * 2) {
      string tmp = "";
      tmp += now[i/2];
      string tmp2 = now[i/2];
      if(i%2 == 1) {
        REP(j, tmp2.size()) {
          if(tmp2[j] == 'A') tmp2[j] = 'B';
          else tmp2[j] = 'A';
        }
      }
      tmp += tmp2;
      next.push_back(tmp);
    }
    now = next;
    len *= 2;
  }
  cout << now.size() << "\n";
  REP(i, now.size()) cout << now[i] << "\n";
}