#!/bin/python3

import sys

def howManyGames(p, d, m, s):
    # Return the number of games you can buy
    ans = 0
    while 1:
        c = max(p - d*ans, m)
        if c <= s:
            s -= c
            ans += 1
        else:
            break
    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)