# -*- coding: utf-8 -*-
"""
No.236 鴛鴦茶
https://yukicoder.me/problems/no/236

"""
import sys
from sys import stdin
input = stdin.readline


def main(args):
    A, B, X, Y = map(int, input().split())
    coffee_limit = X * (A + B) / A
    tea_limit = Y * (A + B) / B
    print(min(coffee_limit, tea_limit))


if __name__ == '__main__':
    main(sys.argv[1:])