#include <bits/stdc++.h>
using namespace std;
typedef signed long long ll;

#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define FORR2(x,y,arr) for(auto& [x,y]:arr)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
template<class T> bool chmax(T &a, const T &b) { if(a<b){a=b;return 1;}return 0;}
template<class T> bool chmin(T &a, const T &b) { if(a>b){a=b;return 1;}return 0;}
//-------------------------------------------------------


ll P,Q,X,Y;

ostream& operator<<(ostream& os, __int128 v) {
	if(v==0) {
		return (os<<'0');
	}
	if(v<0) {
		os<<'-';
		v=-v;
	}
	
	string T;
	while(v) {
		T+=(char)('0'+(v%10));
		v/=10;
	}
	reverse(ALL(T));
	return (os<<T);
}

__int128 rev(__int128 v) {
	__int128 w=0;
	while(v) {
		w=w*10+v%10;
		v/=10;
	}
	return w;
}

void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>P>>Q>>X>>Y;
	FOR(i,10000000) {
		__int128 V=(__int128)i*Q+Y;
		__int128 W=rev(V);
		if(W%P==X) {
			cout<<W<<endl;
			return;
		}
	}
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}