import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {
 static int howManyGames(int p, int d, int m, int s) {
	      int i=0,count=0;int cost;
	        while(s>=0)
	        { if(i==0)
              { s=s-p; 
	           if(s>=0)
	           {count++;}
	           else 
	               return count;
	          }
	        else if(i>=1)
	        { cost=p-(i*d);
	           if(cost>=m&&(s-cost)>=0)
	        	{s=s-cost;
	        	   count++;
	        	}
	           else if(cost<m&&(s-m)>=0)
	           { s=s-m;count++;}
	           else
	        	   return count;
	        }
             else
                 return count;
	       i++;
            }
	     return count;
	 }

	    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 answer = howManyGames(p, d, m, s);
	        System.out.println(answer);
	        in.close();
	    }
   
}