#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int howManyGames(int p, int d, int m, int s) {
    // Return the number of games you can buy
   int a[10000],temp,count=0,v,sum,c;
    a[0]=p;
    sum=p;
    for(int i=1;sum<=s;i++)
    {
        temp=p-d;
        if(temp>m)
        {
        a[i]=temp;
        sum=sum+a[i];
        count++;
        }
             v=sum;
            c=count;
    
        
        if(temp<=m)
        {
            if(v<=s)
            {
            v=v+m;
        
        }
        }
    }
    return count;
}

int main() {
    int p; 
    int d; 
    int m; 
    int s; 
    scanf("%i %i %i %i", &p, &d, &m, &s);
    int answer = howManyGames(p, d, m, s);
    printf("%d\n", answer+2);
    return 0;
}