Katana Thrower

AtCoder

IDabc085_d

Time2000ms

Memory256MB

Difficulty—

You are going out for a walk, when you suddenly encounter a monster. Fortunately, you have $N$ katana (swords), Katana $1$, Katana $2$, $…$, Katana $N$, and can perform the following two kinds of attacks in any order: * Wield one of the katana you have. When you wield Katana $i$ $(1 ≤ i ≤ N)$, the monster receives $a_i$ points of damage. The same katana can be wielded any number of times. * Throw one of the katana you have. When you throw Katana $i$ $(1 ≤ i ≤ N)$ at the monster, it receives $b_i$ points of damage, and you lose the katana. That is, you can no longer wield or throw that katana. The monster will vanish when the total damage it has received is $H$ points or more. At least how many attacks do you need in order to vanish it in total? ## Constraints * $1 ≤ N ≤ 10^5$ * $1 ≤ H ≤ 10^9$ * $1 ≤ a_i ≤ b_i ≤ 10^9$ * All input values are integers. ## Input Input is given from Standard Input in the following format: $N$ $H$ $a_1$ $b_1$ $:$ $a_N$ $b_N$ [samples]

Samples

Input #1

1 10
3 5

Output #1

3

You have one katana. Wielding it deals $3$ points of damage, and throwing it deals $5$ points of damage. By wielding it twice and then throwing it, you will deal $3 + 3 + 5 = 11$ points of damage in a total of three attacks, vanishing the monster.

Input #2

2 10
3 5
2 6

Output #2

2

In addition to the katana above, you also have another katana. Wielding it deals $2$ points of damage, and throwing it deals $6$ points of damage. By throwing both katana, you will deal $5 + 6 = 11$ points of damage in two attacks, vanishing the monster.

Input #3

4 1000000000
1 1
1 10000000
1 30000000
1 99999999

Output #3

860000004

Input #4

Output #4

API Response (JSON)

{
  "problem": {
    "name": "Katana Thrower",
    "description": {
      "content": "You are going out for a walk, when you suddenly encounter a monster. Fortunately, you have $N$ katana (swords), Katana $1$, Katana $2$, $…$, Katana $N$, and can perform the following two kinds of atta",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc085_d"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "You are going out for a walk, when you suddenly encounter a monster. Fortunately, you have $N$ katana (swords), Katana $1$, Katana $2$, $…$, Katana $N$, and can perform the following two kinds of atta...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments