#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> P;
typedef vector<ll> VI;
typedef vector<VI> VVI;
#define REP(i,n) for(ll i=0;i<(n);i++)
#define ALL(v) v.begin(),v.end()
template<typename T> bool chmax(T &x, const T &y) {return (x<y)?(x=y,true):false;};
template<typename T> bool chmin(T &x, const T &y) {return (x>y)?(x=y,true):false;};
constexpr ll MOD=1000000007;
constexpr ll INF=2e18;

int main(){
    ll p, q, x, y; cin >> p >> q >> x >> y;
    string ans;
    ll n;
    for(ll i=0;1;i++){
        if((q*i+y)%10==0)
            continue;
        ans=to_string(q*i+y);
        reverse(ALL(ans));
        n=0;
        REP(j,(int)ans.size()){
            n=n*10%p;
            n=(n+ans[j]-'0')%p;
        }
        if(n!=0)
            break;
        if(n==x)
            break;
    }
    while(n!=x){
        n=n*10%p;
        ans+='0';
    }
    cout << ans << endl;
    return 0;
}