#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
int main() {
    int p; 
    int d; 
    int m; 
    int s,count=0; 
    scanf("%i %i %i %i", &p, &d, &m, &s);
   
 do{ if(p>=m+d)
 {s=s-p;
   p=p-d;}
    else {s=s-p;
         p=m;}
   count=count+1;}
    while(s>=0&&p>=m);
    count=count-1;
    printf("%d",count);
    return 0;
}