Friends

AtCoder

IDabc177_d

Time2000ms

Memory256MB

Difficulty—

There are $N$ persons called Person $1$ through Person $N$. You are given $M$ facts that "Person $A_i$ and Person $B_i$ are friends." The same fact may be given multiple times. If $X$ and $Y$ are friends, and $Y$ and $Z$ are friends, then $X$ and $Z$ are also friends. There is no friendship that cannot be derived from the $M$ given facts. Takahashi the evil wants to divide the $N$ persons into some number of groups so that every person has no friend in his/her group. At least how many groups does he need to make? ## Constraints * $2 \leq N \leq 2\times 10^5$ * $0 \leq M \leq 2\times 10^5$ * $1\leq A_i,B_i\leq N$ * $A_i \neq B_i$ ## Input Input is given from Standard Input in the following format: $N$ $M$ $A_1$ $B_1$ $\vdots$ $A_M$ $B_M$ [samples]

Samples

Input #1

Output #1

3

Dividing them into three groups such as ${1,3}$, ${2,4}$, and ${5}$ achieves the goal.

Input #2

Output #2

Input #3

Output #3

API Response (JSON)

{
  "problem": {
    "name": "Friends",
    "description": {
      "content": "There are $N$ persons called Person $1$ through Person $N$. You are given $M$ facts that \"Person $A_i$ and Person $B_i$ are friends.\" The same fact may be given multiple times. If $X$ and $Y$ are frie",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc177_d"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "There are $N$ persons called Person $1$ through Person $N$.\nYou are given $M$ facts that \"Person $A_i$ and Person $B_i$ are friends.\" The same fact may be given multiple times.\nIf $X$ and $Y$ are frie...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments