import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

void main() {
    int a = readint;
    int b = readint;
    int c = readint;

    auto xs = [tuple(a, "A"), tuple(b, "B"), tuple(c, "C")];
    xs.sort();
    foreach_reverse (x; xs) {
        writeln(x[1]);
    }
}