import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner sc=new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int c=sc.nextInt();
        int d=sc.nextInt();
        
        int unit=1+c;
        int vegetable=0;
        int totalEat=0;
        while(d>=totalEat){
            if(a>0 && b>=c){
                totalEat+=unit;
                a--;
                b-=c;
                vegetable++;
            }else{
                break;
            }
        }
        System.out.println(vegetable);
        
        
        
    }
}