#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint;
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)
#define Inf 1000000001

int main(){
	
	mint::set_mod(90007);
	
	long long P,Q,x,y;
	cin>>P>>Q>>x>>y;
	string ans;
	while(true){
		ans = to_string(y);
		reverse(ans.begin(),ans.end());
		mint cur = stoll(ans);
		if(cur!=0&&y%10!=0)break;
		y += Q;
	}
	
	mint cur = stoll(ans);
	while(cur.val()!=x){
		cur *= 10;
		ans += '0';
	}
	cout<<ans<<endl;
	
	return 0;
}