#include<iostream>
#include<string>
using namespace std;
long long q,p,a,b,s,br,g,g1,a1[17],i,br1,br2,br3,a2[17],fl;
string s2,s1;

int main () {
cin>>a>>b>>q>>p;
s=a/q;
br=s;

if(a%q!=0) {
br++;
}
while(1) {
 g=q*br;
 g1=p*br;

 if(g>b) break;
while(1) {
 br1++;
 a1[br1]=g%10;
 g=g/10;
 if(g<=9) {  
     br1++;
     a1[br1]=g%10;
 g=g/10;
 break; }
}
while(1) {
br2++;
a2[br2]=g1%10;
g1=g1/10;
if(g1<=9)  {  
    br2++;
 a2[br2]=g1%10;
g1=g1/10;
break; }
}

for(i=1;i<=br1;i++) {
if(a1[i]!=a2[(br1-i)+1]) {
fl=0;
break;
}
}



if(fl==1) {
 br3++;

}
fl=1;
br++;
br1=0;
br2=0;
}




 cout<<br3<<endl;
return 0;
}