#include <iostream>
using namespace std;

bool mirrorlook(long long a,long long b)
{
	long long g=0;
	while (b!=0)
	{
		g=g*10;
		g=g+b%10;
		b=b/10;
	}
	if (a==g)
	return true;
	else
	return false;
}

int main()
{
	long long a,b,n,d;
	long long start,stop;
	long long i,br=0;
	
	cin>>a>>b>>n>>d;
	
	start=a/n;
	if (n*start<a)
	start++;
	
	stop=b/n;
	
	
	for (i=start;i<=stop;i++)
	{
		if ( mirrorlook(n*i,d*i) )
		{
			br++;
		}
	}
	cout<<br<<endl;
	return 0;
}