#!/bin/python3

import sys

# 20 3 6 80  = 1 +
# 17 3 6 87 = 1 +
# 14 3 6 70 = 1 + 
# 11 3 6 56 = 1 +
# 8 3 6 48 = 1 +
# 5 3 6 40 = 6

def howManyGames(p, d, m, s):
    # Return the number of games you can buy
    # Base case
    if s < p:
      return 0
    if p <= m:
      p = m
      return s//p
    # 1 + 
    return 1 + howManyGames(p-d, d, m, s-p)

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)