#include using namespace std; typedef long long ll; #define F first #define S second #define pii pair #define eb emplace_back #define all(v) v.begin(), v.end() #define rep(i, n) for (int i = 0; i < n; ++i) #define rep3(i, l, n) for (int i = l; i < n; ++i) #define chmax(a, b) a = (a >= b ? a : b) #define chmin(a, b) a = (a <= b ? a : b) #define out(a) cout << a << endl #define outa(a, n) rep(_, n) cout << a[_] << " "; cout << endl #define SZ(v) (int)v.size() #define inf (int)(1e9+7) #define abs(x) (x >= 0 ? x : -(x)) int main() { ios::sync_with_stdio(false); cin.tie(0); // c, a, b以外無視 int n, d; cin >> n >> d; int tmp = n - d; rep(i, n - abs(tmp)) cout << "A"; rep(i, abs(tmp)) cout << (tmp > 0 ? "C" : "B"); cout << endl; }