ABC

AtCoder

IDarc113_a

Time2000ms

Memory256MB

Difficulty—

Given a positive integer $K$, find the number of triples of positive integers $(A, B, C)$ such that $ABC \leq K$. Two triples that only differ in the order of numbers are also distinguished. ## Constraints * $1\leq K\leq 2\times 10^5$ * $K$ is an integer. ## Input Input is given from Standard Input in the following format: $K$ [samples]

Samples

Input #1

Output #1

4

We have the following triples: $(1,1,1),(1,1,2),(1,2,1),(2,1,1)$.

Input #2

Output #2

Input #3

Output #3

API Response (JSON)

{
  "problem": {
    "name": "A*B*C",
    "description": {
      "content": "Given a positive integer $K$, find the number of triples of positive integers $(A, B, C)$ such that $ABC \\leq K$. Two triples that only differ in the order of numbers are also distinguished.",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "arc113_a"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Given a positive integer $K$, find the number of triples of positive integers $(A, B, C)$ such that $ABC \\leq K$. Two triples that only differ in the order of numbers are also distinguished.\n\n## Const...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments