#!/bin/python3

import sys

def howManyGames(p, d, m, s):
    # Return the number of games you can buy
    sum = 0
    dam = p
    counter = 0
    while sum <= s:
        if dam> m:
            sum = sum + dam
            dam = dam - d
            counter = counter +1
        else:
            sum = sum + m
            counter = counter +1
    if sum==s:
        return(counter)
    else:
        return(counter-1)
            
            
            
            
            
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)