var list = [Int]()
let names = ["A","B","C"]
var nameDic = [Int:String]()
for i in 0..<3 {
    let inpt = Int(readLine()!)!
    list.append(inpt)
    nameDic[inpt] = names[i]
}
list = list.sorted().reversed()

for tall in list {
    print(nameDic[tall]!)
}