AtCoder Beginner Contest 090
D
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原题
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Problem Statement

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Takahashi had a pair of two positive integers not exceeding $N$, $(a,b)$, which he has forgotten. He remembers that the remainder of $a$ divided by $b$ was greater than or equal to $K$. Find the number of possible pairs that he may have had.

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Constraints

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  • $1 \leq N \leq 10^5$
  • $0 \leq K \leq N-1$
  • All input values are integers.
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Input

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Input is given from Standard Input in the following format:

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N K

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Output

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Print the number of possible pairs that he may have had.

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样例

Input #1
5 2
Output #1
7
There are seven possible pairs: $(2,3),(5,3),(2,4),(3,4),(2,5),(3,5)$ and $(4,5)$.
Input #2
10 0
Output #2
100
Input #3
31415 9265
Output #3
287927211
题目信息
题号
arc091_b
时间限制
2 s
内存限制
256 MB

题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。