CF1362A.Johnny and Ancient Computer

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

Johnny has recently found an ancient, broken computer. The machine has only one register, which allows one to put in there one variable. Then in one operation, you can shift its bits left or right by at most three positions. The right shift is forbidden if it cuts off some ones. So, in fact, in one operation, you can multiply or divide your number by 22 , 44 or 88 , and division is only allowed if the number is divisible by the chosen divisor.

Formally, if the register contains a positive integer xx , in one operation it can be replaced by one of the following:

  • x2x \cdot 2
  • x4x \cdot 4
  • x8x \cdot 8
  • x/2x / 2 , if xx is divisible by 22
  • x/4x / 4 , if xx is divisible by 44
  • x/8x / 8 , if xx is divisible by 88

For example, if x=6x = 6 , in one operation it can be replaced by 1212 , 2424 , 4848 or 33 . Value 66 isn't divisible by 44 or 88 , so there're only four variants of replacement.

Now Johnny wonders how many operations he needs to perform if he puts aa in the register and wants to get bb at the end.

输入格式

The input consists of multiple test cases. The first line contains an integer tt ( 1t10001 \leq t \leq 1000 ) — the number of test cases. The following tt lines contain a description of test cases.

The first and only line in each test case contains integers aa and bb ( 1a,b10181 \leq a, b \leq 10^{18} ) — the initial and target value of the variable, respectively.

输出格式

Output tt lines, each line should contain one integer denoting the minimum number of operations Johnny needs to perform. If Johnny cannot get bb at the end, then write 1-1 .

输入输出样例

  • 输入#1

    10
    10 5
    11 44
    17 21
    1 1
    96 3
    2 128
    1001 1100611139403776
    1000000000000000000 1000000000000000000
    7 1
    10 8

    输出#1

    1
    1
    -1
    0
    2
    2
    14
    0
    -1
    -1

说明/提示

In the first test case, Johnny can reach 55 from 1010 by using the shift to the right by one (i.e. divide by 22 ).

In the second test case, Johnny can reach 4444 from 1111 by using the shift to the left by two (i.e. multiply by 44 ).

In the third test case, it is impossible for Johnny to reach 2121 from 1717 .

In the fourth test case, initial and target values are equal, so Johnny has to do 00 operations.

In the fifth test case, Johnny can reach 33 from 9696 by using two shifts to the right: one by 22 , and another by 33 (i.e. divide by 44 and by 88 ).

首页