ABC conjecture

AtCoder

IDabc227_c

Time2000ms

Memory256MB

Difficulty—

You are given a positive integer $N$. Find the number of triples of positive integers $(A, B, C)$ such that $A\leq B\leq C$ and $ABC\leq N$. The Constraints guarantee that the answer is less than $2^{63}$. ## Constraints * $1 \leq N \leq 10^{11}$ * $N$ is an integer. ## Input Input is given from Standard Input in the following format: $N$ [samples]

Samples

Input #1

Output #1

5

There are five such triples: $(1,1,1),(1,1,2),(1,1,3),(1,1,4),(1,2,2)$.

Input #2

Output #2

Input #3

100000000000

Output #3

5745290566750

API Response (JSON)

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      "content": "You are given a positive integer $N$. Find the number of triples of positive integers $(A, B, C)$ such that $A\\leq B\\leq C$ and $ABC\\leq N$. The Constraints guarantee that the answer is less than $2^{",
      "description_type": "Markdown"
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    "platform": "AtCoder",
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      "memory_limit": 262144
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    "difficulty": "None",
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      "statement_type": "Markdown",
      "content": "You are given a positive integer $N$.\nFind the number of triples of positive integers $(A, B, C)$ such that $A\\leq B\\leq C$ and $ABC\\leq N$.\nThe Constraints guarantee that the answer is less than $2^{...",
      "is_translate": false,
      "language": "English"
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