#!/bin/python3

import sys

def howManyGames(p, d, m, s):
    # Return the number of games you can buy
    no = 0
    while(s>0):
        if(s>=p):
            no+=1
        s -= p
        if(p-d<m):
            p = m
        else:
            p = p-d
    return no
    
    #print(p,s)
    '''
    if(s<=p):
        return 0
    else:
        if(p<m):
            return(1+howManyGames(m,d,m,s-m))
        else:
            return(1+howManyGames(p-d,d,m,s-p))
        elif(p-d<=m):
            return(1+howManyGames(m,d,m,s-p))
        else:
            return 0
        '''    

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)