import java.util.*;
public class time{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int p = sc.nextInt();
		int d = sc.nextInt();
		int m = sc.nextInt();
		int s = sc.nextInt();
		int answer = 0;
		while(s >= p){
			s = s - p;
			if(p > d + m)
				p = p - d;
			else 
				p = m;
			answer++;
			

		}
		System.out.println(answer);



	}
}