package main
import(
	"fmt"
	"sort"
)

func output(ele int, heightMap map[string]int){
	if ele == heightMap["A"]{
		fmt.Println("A")
	} else if ele == heightMap["B"]{
		fmt.Println("B")
	} else if ele == heightMap["C"]{
		fmt.Println("C")
	}
}

func main(){
	var heightA, heightB, heightC int
	fmt.Scan(&heightA, &heightB, &heightC)
	heightList := []int{heightA, heightB, heightC}
	sort.Sort(sort.IntSlice(heightList))
	heightMap := map[string]int{"A": heightA, "B": heightB, "C": heightC}

	for i := len(heightList) - 1; i >= 0; i--{
		output(heightList[i], heightMap)
	}
}