Built?

AtCoder
IDarc076_b
Time2000ms
Memory256MB
Difficulty
There are $N$ towns on a plane. The $i$\-th town is located at the coordinates $(x_i,y_i)$. There may be more than one town at the same coordinates. You can build a road between two towns at coordinates $(a,b)$ and $(c,d)$ for a cost of $min(|a-c|,|b-d|)$ yen (the currency of Japan). It is not possible to build other types of roads. Your objective is to build roads so that it will be possible to travel between every pair of towns by traversing roads. At least how much money is necessary to achieve this? ## Constraints * $2 ≤ N ≤ 10^5$ * $0 ≤ x_i,y_i ≤ 10^9$ * All input values are integers. ## Input Input is given from Standard Input in the following format: $N$ $x_1$ $y_1$ $x_2$ $y_2$ : $x_N$ $y_N$ [samples]
Samples
Input #1
3
1 5
3 9
7 8
Output #1
3

Build a road between Towns $1$ and $2$, and another between Towns $2$ and $3$. The total cost is $2+1=3$ yen.
Input #2
6
8 3
4 9
12 19
18 1
13 5
7 6
Output #2
8
API Response (JSON)
{
  "problem": {
    "name": "Built?",
    "description": {
      "content": "There are $N$ towns on a plane. The $i$\\-th town is located at the coordinates $(x_i,y_i)$. There may be more than one town at the same coordinates. You can build a road between two towns at coordinat",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "arc076_b"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "There are $N$ towns on a plane. The $i$\\-th town is located at the coordinates $(x_i,y_i)$. There may be more than one town at the same coordinates.\nYou can build a road between two towns at coordinat...",
      "is_translate": false,
      "language": "English"
    }
  ]
}
Full JSON Raw Segments