#include <stdio.h>

int main (void){
	int a,b,c,d,e=0;
	char f,s,t;
	scanf("%d%d%d",&a,&b,&c);d=b;
	if(a>b){f=s='A';t='B';}else{b=a;a=d;f=s='B';t='A';e=1;}
	if(c>a)f='C';else{s=b>c?e==1?'A':'B':'C'; t=b>c?'C':e==1?'A':'B';}
	printf("%c\n%c\n%c\n",f,s,t);
	return(0);
}