P15556 [CodeChef] CHFMOT18
普及-
题目描述

In a country called Chef Land, there was a lot of monetary fraud, so Chefu, the head of the country, decided to choose new denominations of the local currency ― all even-valued coins up to an integer $N$ should exist. After a few days, a citizen complained that there was no way to create an odd value, so Chefu decided that he should also introduce coins with value $1$. Formally, you are given an integer $N$; for $v = 1$ and each even positive integer $v \le N$, coins with value $v$ exist.
You are also given an integer $S$. To handle transactions quickly, find the minimum number of coins needed to pay a price $S$.

-----Input-----
- The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
- The first and only line of each test case contains two space-separated integers $S$ and $N$.

-----Output-----
For each test case, print a single line containing one integer ― the minimum number of coins.

-----Constraints-----
- $1 \le T \le 10,000$
- $1 \le S \le 10^9$
- $2 \le N \le 10^9$
- $N$ is even

-----Subtasks-----
Subtask #1 (100 points): original constraints

-----Example Input-----
4
2 2
1 14
30 10
31 4

-----Example Output-----
1
1
3
9

-----Explanation-----
Example case 1: One coin with value $2$ is sufficient.
Example case 2: We need to use one coin with value $1$.
Example case 3: We need $3$ coins, each with value $10$.
Example case 4: We can use seven coins with value $4$, one coin with value $2$ and one coin with value $1$.

输入格式

见题面

输出格式

见题面

样例输入
['4', '2 2', '1 14', '30 10', '31 4']
样例输出
['1', '1', '3', '9']