#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define loop(i,a,b) for(int i=a;i pii; typedef vector vi; typedef vector vvi; typedef vector vp; typedef vector vvp; typedef vector vs; typedef vector vd; typedef vector vvd; typedef pair pip; typedef vectorvip; const double PI=acos(-1); const double EPS=1e-7; const int inf=1e8; const ll INF=1e16; int dx[4]={0,1,0,-1}; int dy[4]={1,0,-1,0}; int main(){ ll a,b,c,d; cin>>a>>b>>c>>d; ll t=(a*b)%c; if(t==0)t=c; if(d==t)cout<<"YES"<