// yukicoder: No.582 キャンディー・ボックス３
// 2019.8.2 bal4u

#include <stdio.h>

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif
int in() {   // 非負整数の入力
	int n = 0, c = gc();
	//	while (isspace(c)) c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

int main()
{
	int i, N, c, one, two, many;

	N = in(), one = two = many = 0;
	for (i = 0; i < N; i++) {
		if (c = in()) {
			if (c == 1) one++;
			else if (c == 2) two++;
			else many++;
		}
	}
	puts((one & 1) && two <= 1 && many == 0? "A": "B");
	return 0;
}