#!/bin/python3

import sys

def howManyGames(p, d, m, s):
    ans=0
    nextCost=max(p,m)
    while s>=nextCost:
        p-=d
        s-=nextCost
        #print(p,d,m,s)
        nextCost=max(p,m)
        ans+=1
    return ans

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)