#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char rbuf[1<<22];

main(){
	int n=read(0,rbuf,sizeof rbuf);
	short*rp_end=rbuf+n-1;
	short*rp=rp_end;
	while(*--rp==0x3120);
	write(1,rp_end-rp&1?"Alice":"Bob  ",5);
	_exit(0);
}