from sys import stdin

def main():
    A, B, C, D = map(int, input().split())

    yasai, niku = 0, 0
    ans = 0
    for a in range(1, A + 1):
        meat = a * C
        if meat <= B and a + meat <= D:
            ans = a
        else:
            print(ans)
            break

input = lambda: stdin.readline()
main()