#include<bits/stdc++.h>
#define rep(i,n)for(int i=0;i<(n);i++)
using namespace std;

int cnt[26];
int main() {
	int n, d; scanf("%d%d", &n, &d);
	string a = "ADOPQR", b = "B";
	for (char c : a)cnt[c - 'A'] = 1;
	for (char c : b)cnt[c - 'A'] = 2;
	rep(t, n) {
		if ((n - t - 1) * 2 + 1 < d) {
			printf("%c", 'B'); d -= 2; continue;
		}
		rep(i, 26) {
			if (cnt[i] <= d) {
				printf("%c", 'A' + i); d -= cnt[i]; break;
			}
		}
	}
	cout << endl;
}