package main

import (
	"fmt"
)

func main() {
	solve()
}


var grundy [100+1]int
func solve(){
	var N int
	fmt.Scan(&N)
	grundy[0]=0
	for i:=2; i<=N; i++ {
	    set := map[int]bool{}
		set[grundy[i/2]^grundy[(i+1)/2]]=true
		if i>=3{
			set[grundy[i/3]^grundy[(i+1)/3]^grundy[(i+2)/3]]=true
		}
		for set[grundy[i]]{
			grundy[i]++
		}
	}
	if grundy[N]!=0{
		fmt.Println("A")
	}else{
		fmt.Println("B")
	}
}