#include <stdio.h>

struct Person{
    char name;
    int height;
};

int main(void){
    struct Person p[3];
    int i, k, t;
    char n;
    for(i = 0; i < 3; i++){
        scanf("%d", &p[i].height);
        p[i].name = 'A' + i;
    }
    do{
        k = 0;
        for(i = 0; i < 2; i++){
            if(p[i].height < p[i+1].height){
                t = p[i].height;
                p[i].height = p[i+1].height;
                p[i+1].height = t;
                n = p[i].name;
                p[i].name = p[i+1].name;
                p[i+1].name = n;
                k++;
            }
        }
    }while(k != 0);
    for(i = 0; i < 3; i++){
        printf("%c\n", p[i].name);
    }
}