#include <stdio.h>

typedef struct {
	char name;
	int h, w;
}data;

int main(void)
{
	data a = { 65 }, b = { 66 }, c = { 67 }, t;
	int i;
	scanf("%d%d%d%d%d%d", &a.h, &a.w, &b.h, &b.w, &c.h, &c.w);
	for (i = 0; i < 2; i++) {
		if (a.h < b.h) {
			t = a;
			a = b;
			b = t;
		}
		if (b.h < c.h) {
			t = b;
			b = c;
			c = t;
		}
	}
	if (a.h == b.h == c.h) {
		for (i = 0; i < 2; i++) {
			if (a.w > b.w) {
				t = a;
				a = b;
				b = t;
			}
			if (b.w > c.w) {
				t = b;
				b = c;
				c = t;
			}
		}
	}
	else if (a.h == b.h&&a.w > b.w) {
		t = a;
		a = b;
		b = t;
	}
	else if (b.h == c.h&&b.w > c.w) {
		t = b;
		b = c;
		c = t;
	}
	else if (a.h == c.h&&a.w > c.w) {
		t = a;
		a = c;
		c = t;
	}
	printf("%c\n%c\n%c", a.name, b.name, c.name);
	return 0;
}