Codeforces Round 1000 (Div. 2) |
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Finished |
A segment of positive integers $$$[l,r]$$$ is called coprime if $$$l$$$ and $$$r$$$ are coprime$$$^{\text{∗}}$$$.
A coprime segment $$$[l,r]$$$ is called minimal coprime if it does not contain$$$^{\text{†}}$$$ any coprime segment not equal to itself. To better understand this statement, you can refer to the notes.
Given $$$[l,r]$$$, a segment of positive integers, find the number of minimal coprime segments contained in $$$[l,r]$$$.
$$$^{\text{∗}}$$$Two integers $$$a$$$ and $$$b$$$ are coprime if they share only one positive common divisor. For example, the numbers $$$2$$$ and $$$4$$$ are not coprime because they are both divided by $$$2$$$ and $$$1$$$, but the numbers $$$7$$$ and $$$9$$$ are coprime because their only positive common divisor is $$$1$$$.
$$$^{\text{†}}$$$A segment $$$[l',r']$$$ is contained in the segment $$$[l,r]$$$ if and only if $$$l \le l' \le r' \le r$$$.
Each test contains multiple test cases. The first line contains the number of test cases $$$t$$$ ($$$1 \le t \le 100$$$). The description of the test cases follows.
The only line of each test case consists of two integers $$$l$$$ and $$$r$$$ ($$$1 \le l \le r \le 10^9$$$).
For each test case, output the number of minimal coprime segments contained in $$$[l,r]$$$, on a separate line.
61 21 1049 4969 4201 19982 44353
1 9 0 351 1 34371
On the first test case, the given segment is $$$[1,2]$$$. The segments contained in $$$[1,2]$$$ are as follows.
Therefore, the segment $$$[1,2]$$$ contains $$$1$$$ minimal coprime segment.
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