#!/usr/bin/env python3
"""Solution for: https://www.hackerrank.com/contests/hourrank-23/challenges/halloween-sale
"""

import sys


def game_count(p: int, d: int, m, s) -> int:
    count = 0
    while s > 0:
        if s >= max(p, m):
            s -= max(p, m)
            p -= d
            count += 1
        else:
            break
    return count


def main():
    """Print ..."""
    p, d, m, s = [int(x) for x in input().split()]
    result = game_count(p, d, m, s)
    print(result)


if __name__ == '__main__':
    main()