def main():
    a, b, c, d = map(int, input().split())
    ans = 0
    while True:
        if ans + 1 <= a:
            if (ans + 1) * c <= b:
                if (ans + 1) * (c + 1) <= d:
                    ans += 1
                else:
                    break
            else:
                break
        else:
            break
    print(ans)
if __name__ =='__main__':
    main()