#include <stdio.h>
int main(void){
	int H[3];
	char name[4] = "ABC" ;
	int change;
	
	for(int i = 0; i < 3; i++){
		scanf("%d",&H[i]);
	}
	
	for(int j = 0; j < 2; j++){
		for(int k = j; k < 3; k++){
			if(H[j] < H[k]){
				change = H[j];
				H[j] = H[k];
				 H[k] = change;
				 
				 change = name[j];
				 name[j] = name[k];
				 name[k] = change;
			}
		}
	}
	
	for(int l = 0; l < 3; l++){
		printf("%c\n",name[l]);
	}
	
//	printf("%c",name[0]);		//	check ok
	return 0;
}