#include<iostream>
using namespace std;
unsigned long long a,b,n,d,p,q;
int main()
{
    string s,s1;
    unsigned long long i,g,h,x,y,br=0,j;
    int l=0;
    cin>>a>>b>>n>>d;
    if(a%n==0)i=a/n;
    else i=a/n+1;
    while(p!=(b/n))
    {
        s="";
        s1="";
        p=n*i;
        q=d*i;
        x=0;
        y=0;
        if(p>b)break;
        j=0;
        while(p)
        {
            s+=char((p%10)+'0');
            p/=10;
            x++;
        }
        while(q)
        {
            s1+=char((q%10)+'0');
            q/=10;
            y++;
        }
        if(x==y)
        {
            h=y-1;
            for(g=0;g<x;g++)
            {
                if(s[g]!=s1[h])
                {
                    l=1;
                    break;
                }
                h--;
            }
            if(l==0)br++;
        }
        l=0;
        i++;
    }
    cout<<br<<endl;
    return 0;
}