#include <stdio.h>
#include <stdlib.h>

#define G_LEN (3)

int main()
{
	int H[G_LEN], Hs[G_LEN] = { 'A','B','C' }, max = 0, maxh = 0;

	for (int i = 0; i < G_LEN; i++) {
		if (scanf("%d", &H[i]) != 1) {
			return -1;
		}
	}

	for (int i = 0; i < G_LEN; i++) {
		max = 0;
		maxh = 0;
		for (int j = 0; j < G_LEN; j++) {
			if (H[j] > max) {
				max = H[i];
				maxh = i;
			}
		}
		printf("%c\n", Hs[maxh]);
		H[maxh] = 0;
	}

	return 0;
}