Problem D

Statement
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Description:
For two positive integers $$$l$$$ and $$$r$$$ ($$$l \le r$$$) let $$$c(l, r)$$$ denote the number of integer pairs $$$(i, j)$$$ such that $$$l \le i \le j \le r$$$ and $$$\operatorname{gcd}(i, j) \ge l$$$. Here, $$$\operatorname{gcd}(i, j)$$$ is the greatest common divisor (GCD) of integers $$$i$$$ and $$$j$$$.

YouKn0wWho has two integers $$$n$$$ and $$$k$$$ where $$$1 \le k \le n$$$. Let $$$f(n, k)$$$ denote the minimum of $$$\sum\limits_{i=1}^{k}{c(x_i+1,x_{i+1})}$$$ over all integer sequences $$$0=x_1 \lt x_2 \lt \ldots \lt x_{k} \lt x_{k+1}=n$$$.

Help YouKn0wWho find $$$f(n, k)$$$.

Input Format:
The first line contains a single integer $$$t$$$ ($$$1 \le t \le 3 \cdot 10^5$$$) — the number of test cases.

The first and only line of each test case contains two integers $$$n$$$ and $$$k$$$ ($$$1 \le k \le n \le 10^5$$$).

Output Format:
For each test case, print a single integer — $$$f(n, k)$$$.

Note:
In the first test case, YouKn0wWho can select the sequence $$$[0, 2, 6]$$$. So $$$f(6, 2) = c(1, 2) + c(3, 6) = 3 + 5 = 8$$$ which is the minimum possible.

Submissions

IDLanguageExit CodeTimestampCodeStdoutStderrRetry
5665 go 0 2026-03-19T03:37:14.344866Z View View View Retry
5650 go 1 2026-03-19T03:29:15.398618Z View View View Retry

Evaluations

Eval IDRun IDProviderModelLangSuccessTimestampPromptResponseStdoutStderrRetry
2951 20260318-220006 openai gpt-5.4 go false 2026-03-19T00:25:50.197421Z View View View View Retry
2188 20260311-031437 gemini gemini-3-pro-preview go false 2026-03-11T04:43:51.007466Z View View View View Retry