#!/bin/python3

import sys

def howManyGames(p, d, m, s):
    # Return the number of games you can buy
    i=p
    ct=0
    while s>=0:
        #print(i)
        if i<=m:
            s=s-m
            #ct+=1
            
        else:
            s=s-i
            i=i-d
            #ct+=1
        if s>=0:
            ct+=1
    return ct
if __name__ == "__main__":
    p, d, m, s = input().strip().split(' ')
    p, d, m, s = [int(p), int(d), int(m), int(s)]
    answer = howManyGames(p, d, m, s)
    print(answer)