#!/bin/python3

import sys

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

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)