#include<iostream>
#include<algorithm>
#include<cmath>
using namespace std;
int main ()
{     
    int yes,x,lol,n,d,a,b,y=0,br=0,g=1;
    cin>>a>>b>>n>>d;
    for(x=a; x<=b; x++)
    {   
        if(x/n==double(x/n))break;
        else
        {
        lol=x;
        yes=x;
        while(x)
        {
            x=x/10;
            g=g*10;
        }
        g/=10;
        while(g)
        {
            y=y+(g*(yes%10));
            yes/=10;
            g/=10;
        }
        if((lol/y)==(n/d))br++;
    }
    }
    cout<<br<<endl;
    return 0;
}