#include <iostream>
#include <cstring>

using namespace std;

bool isAreverseofB (long long A, long long B)
{
	long long C = 0;
	while (A > 0)
	{
		C = (C * 10) + (A % 10);
		A /= 10;
	}
	
	return B == C ? true : false;
}

int main ()
{	
	long long a, b;
	int n, d;
	cin >> a >> b >> n >> d;
	long long p = a + ((a + n) % n), q;
	
	int count = 0;
	while (p < b)
	{
		q = p / n * d;
		count += isAreverseofB(p, q);
		p += n;
	}

	cout << count << endl;
	
	return 0;
}
