import std.experimental.all;

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() {
    auto a = readints;
    auto b = readints;
    auto c = readints;

    auto xs = [[-a[0], a[1], 0], [-b[0], b[1], 1], [-c[0], c[1], 2]];
    foreach (x; xs.sort().map!(e => e[2]))
        writeln(to!char(x + 'A'));
}