Little Rabbit is interested in radix. In a positional numeral system, the radix is the number of unique digits, including the digit $0$, used to represent numbers. For example, for the decimal system (the most common system in use today) the radix is ten, because it uses the ten digits from $0$ to $9$. Generally, in a system with radix $b$ ($b > 1$), a string of digits $d_1 \dots d_n$ denotes the number $d_1b^{n-1} + d_2b^{n-2} + \dots + d_nb^0$, where $0 \le d_i < b$.
Little Rabbit casually writes down an equation. He wonders which radix this equation fits.
InputThe are several test cases. Each test case contains a string in a line, which represents the equation Little Rabbit writes down. The length of the string is at most $15$. The input is terminated by the end-of-file.
The equation's format: number, operator, number, $=$, number. There's no whitespace in the string.
Each number has at least $1$ digit, which may contain digital numbers $0$ to $9$ or uppercase letters $A$ to $F$ (which represent decimal $10$ to $15$). The number is guaranteed to be a non-negative integer, which means it doesn't contain the radix point or negative sign. But the number may contain leading zeros.
The operator refers to one of $+$, $-$, $*$, or $/$. It is guaranteed that the number after $/$ will not be equal to $0$. Please note that the division here is not integer division, so $7/2=3$ is not correct.OutputFor each test case, output an integer $r$ ($2 \le r \le 16$) in a line, which means the equation is correct in the system with radix $r$. If there are multiple answers, output the minimum one. If there is no answer between $2$ and $16$, output $-1$.Sample Input
本文首先介绍下MongoDB的基本的增删改查操作,然后,详细介绍MongoDB提供的修改器,以完成各种各样的文档更新操作 MongoDB的主要操作
show dbs 显示当前用户能看到哪些数据库
use foobar 将数据库切换到foobar
show collections 显示当前数据库有哪些集合
db.people.update,update不带参数,可
The alert log is a chronological log of messages and errors, and includes the following items:
All internal errors (ORA-00600), block corruption errors (ORA-01578), and deadlock errors (ORA-00060)
由于几年前写了几篇 CAS 系列的文章,之后陆续有人参照文章去实现,可都遇到了各种问题,同时经常或多或少的收到不少人的求助。现在这时特此说明几点:
1. 那些文章发表于好几年前了,CAS 已经更新几个很多版本了,由于近年已经没有做该领域方面的事情,所有文章也没有持续更新。
2. 文章只是提供思路,尽管 CAS 版本已经发生变化,但原理和流程仍然一致。最重要的是明白原理,然后
lesson 课
traffic 交通
matter 要紧;事物
happy 快乐的,幸福的
second 第二的
idea 主意;想法;意见
mean 意味着
important 重要的,重大的
never 从来,决不
afraid 害怕 的
fifth 第五的
hometown 故乡,家乡
discuss 讨论;议论
east 东方的
agree 同意;赞成
bo
这次看下spring中少见的注解@primary注解,例子
@Component
public class MetalSinger implements Singer{
@Override
public String sing(String lyrics) {
return "I am singing with DIO voice