import java.util.*;
class Hack1{

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int p = in.nextInt();
        int d = in.nextInt();
        int m = in.nextInt();
        int s = in.nextInt();
        int ans=0;
        while(s>=p&&p>m)
        {
            ans++;
            s=s-p;
            p=p-d;
        }
        if(p<m)
            p=m;
        while(s>=p)
        {
            ans++;
            s=s-p;
        }
        System.out.println(ans);
        
    }
}