ι⊥l

AtCoder

IDabc058_a

Time2000ms

Memory256MB

Difficulty—

Three poles stand evenly spaced along a line. Their heights are $a$, $b$ and $c$ meters, from left to right. We will call the arrangement of the poles _beautiful_ if the tops of the poles lie on the same line, that is, $b-a = c-b$. Determine whether the arrangement of the poles is beautiful. ## Constraints * $1 \leq a,b,c \leq 100$ * $a$, $b$ and $c$ are integers. ## Input Input is given from Standard Input in the following format: $a$ $b$ $c$ [samples]

Samples

Input #1

2 4 6

Output #1

YES

Since $4-2 = 6-4$, this arrangement of poles is beautiful.

Input #2

2 5 6

Output #2

NO

Since $5-2 \neq 6-5$, this arrangement of poles is not beautiful.

Input #3

3 2 1

Output #3

YES

Since $1-2 = 2-3$, this arrangement of poles is beautiful.

API Response (JSON)

{
  "problem": {
    "name": "ι⊥l",
    "description": {
      "content": "Three poles stand evenly spaced along a line. Their heights are $a$, $b$ and $c$ meters, from left to right. We will call the arrangement of the poles _beautiful_ if the tops of the poles lie on the s",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc058_a"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Three poles stand evenly spaced along a line. Their heights are $a$, $b$ and $c$ meters, from left to right. We will call the arrangement of the poles _beautiful_ if the tops of the poles lie on the s...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments