#include <stdio.h>

int main()
{
	int a,b,c,d;
	scanf("%d%d%d%d",&a,&b,&c,&d);
	if(c==a+b-1)
	{
		printf("Alice");
		return 0;
	}
	
	if((a+b-c)%2==0)
	{
		int c2 = 1;
		if(d==1) c2 = 0;
		
		if(b-a >=c && c%2 == c2) printf("Alice");
		else if(a-b >=c && c2 == 0) printf("Alice");
		else printf("Bob");
	}
	else
	{
		int val = a+b-c;
		if(b<= val/2)
		{
			if(d==-1)
			{
				printf("Bob");
				return 0;
			}
		}
		if(a<= val/2)
		{
			int c1,c2;
			c1 = (b-(val-a));
			if(d==-1) c2 = 1;
			else c2 = 0;
			if(c1!=c2)
			{
				printf("Bob");
				return 0;
			}
		}
		printf("Alice");
	}
}