Language: C++

#define _USE_MATH_DEFINES
#pragma region include
#include <iostream>
#include <iomanip>
#include <stdio.h>

#include <sstream>
#include <algorithm>
#include <iterator>
#include <cmath>
#include <complex>

#include <string>
#include <cstring>
#include <vector>
#include <bitset>

#include <queue>
#include <set>
#include <map>
#include <stack>
#include <list>

#include <ctime>
////
//#include <random>//
#pragma endregion //#include
/////////

#pragma region typedef
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
#pragma endregion //typedef
////定数
const int INF = (int)1e9;
const LL MOD = (LL)1e9+7;
const LL LINF = (LL)4e18+20;
const LD PI = acos(-1.0);
const double EPS = 1e-9;
/////////
using namespace::std;

//実験での、推測から。
LL getGrundy(LL yama){
	int count = 0;
	while(yama && yama%2==0){
		++count;
		yama /= 2;
	}
	LL ans = 1;
	ans <<= count;
	return ans;
}
map<string,int> memo;//1:通過 2:着地
LL dfs(string& str,LL dep){
	LL ret = 0;
	if( memo.find(str) == memo.end() )
	{//この先には山がすべて残ってる。
		ret = getGrundy( dep );
	}
	else if( memo[str] == 2 )//ここから先にはいけない
	{
		ret = getGrundy( 0 );
	}
	else
	{
		ret ^= dfs(str+"0",dep-1);
		ret ^= dfs(str+"1",dep-1);
	}
	return ret;
}
void solve(){
	/*
	const int depth = 10000;
	vector<int> grun(depth+1,-1);
	grun[0] = 0;//負けの状態、操作が出来ない
	for(int d=1;d<=depth;++d){
		vector<int> g;
		g.push_back( grun[0] );//一番上の頂点を選ぶ。
		int now = grun[0];
		for(int i= d-1;i>=1;--i){
			now ^= grun[i];
			g.push_back( now );
		}
		UNIQUE(g);
		int size = g.size();
		for(int i=0;i<size;++i){
			if( i != g[i] ){
				grun[d] = i;
				break;
			}
		}
		if( grun[d] == -1 ){
			grun[d] = size;
		}
		cerr << d << "\t" << grun[d];
		int count = 0;
		int temp = d;
		while(temp%2 == 0){
			++count;
			temp /= 2;
		}
		int test = (1<<count);
		cerr << "\t" << test;
		if( grun[d] != test ){
			cerr<<"xxxxxxxxxxxxxx"<<endl;
			return;
		}
		cerr << endl;
	}
	*/
	//////////////
	int N;
	LL L;
	cin>>N>>L;
	memo[""] = 1;//通過
	for(int i=0;i<N;++i){
		string str;
		cin>> str;
		int size = str.size();
		for(int i=0;i<size;++i){
			if( i<size-1 ){
				memo[str.substr(0,i+1)] = 1;
			}else{
				memo[str] = 2;
			}
		}
	}

	string temp = "";
	LL ans = dfs(temp,L+1);
	
	cerr << ans << endl;
	
	cout<< (ans!=0?"Alice":"Bob") << endl;
}

#pragma region main
signed main(void){
	std::cin.tie(0);
	std::ios::sync_with_stdio(false);
	std::cout << std::fixed;//小数を10進数表示
	cout << setprecision(16);//小数点以下の桁数を指定//coutとcerrで別	

	solve();
}
#pragma endregion //main()


Compiler output:
a.cc: In function 'LL dfs(std::string&, LL)':
a.cc:68:31: error: cannot bind non-const lvalue reference of type 'std::string&' {aka 'std::__cxx11::basic_string<char>&'} to an rvalue of type 'std::__cxx11::basic_string<char>'
   68 |                 ret ^= dfs(str+"0",dep-1);
      |                            ~~~^~~~
a.cc:56:16: note:   initializing argument 1 of 'LL dfs(std::string&, LL)'
   56 | LL dfs(string& str,LL dep){
      |        ~~~~~~~~^~~
a.cc:69:31: error: cannot bind non-const lvalue reference of type 'std::string&' {aka 'std::__cxx11::basic_string<char>&'} to an rvalue of type 'std::__cxx11::basic_string<char>'
   69 |                 ret ^= dfs(str+"1",dep-1);
      |                            ~~~^~~~
a.cc:56:16: note:   initializing argument 1 of 'LL dfs(std::string&, LL)'
   56 | LL dfs(string& str,LL dep){
      |        ~~~~~~~~^~~