Remainder Reminder

AtCoder

IDarc091_b

Time2000ms

Memory256MB

Difficulty—

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. ## Constraints * $1 \leq N \leq 10^5$ * $0 \leq K \leq N-1$ * All input values are integers. ## Input Input is given from Standard Input in the following format: $N$ $K$ [samples]

Samples

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

Input #3

31415 9265

Output #3

287927211

API Response (JSON)

{
  "problem": {
    "name": "Remainder Reminder",
    "description": {
      "content": "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 numbe",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "arc091_b"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "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 numbe...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments