#include<iostream> using namespace std; int main(){ int a,b,c,n; cin>>a>>b>>c>>n; int d=n1000; if(ab*c>=d){ cout<<"Yes"; }else{ cout<<"No"; } }

#include<iostream> using namespace std; int main(){ long long a,b,c,d; cin>>a>>b>>c>>d; if(abc>=d*1000){ cout<<"Yes"; } else{ cout<<"No"; } return 0; }