from posixpath import split


def main():
    a, b, c, d = (int(x) for x in input().split())
    vegi_n = 0
    meet_n = 0
    for i in range(10):
        vegi_n += 1
        meet_n += c
        vm_n = vegi_n + meet_n


        if meet_n > b:
            print(vegi_n - 1)
            break
        elif vm_n > d:
            print(vegi_n - 1)
            break
        

        

if __name__ == '__main__':
    main()