#!/bin/python

import sys

def howManyGames(p, d, m, s):
    i = 0
    while s > 0:
        if p > m:
            if s - p >= 0:
                i+=1
            s = s - p
            p = p - d
            
        if p <= m:
            if s - m >= 0:
                i+=1
            s = s - m
            
    return i

if __name__ == "__main__":
    p, d, m, s = raw_input().strip().split(' ')
    p, d, m, s = [int(p), int(d), int(m), int(s)]
    answer = howManyGames(p, d, m, s)
    print answer