Cabbages

AtCoder

IDabc210_a

Time2000ms

Memory256MB

Difficulty—

Takahashi is visiting a shop specializing in cabbage. The shop sells cabbage for $X$ yen (Japanese currency) per head. However, if you buy more than $A$ heads of cabbage at once, the $(A+1)$\-th and subsequent heads will be sold for $Y$ yen per head. (It is guaranteed that $Y \lt X$. See Sample Input/Output 1 for clarity.) Print the amount of money needed to buy $N$ heads of cabbage. ## Constraints * $1 \leq N \leq 10^5$ * $1 \leq A \leq 10^5$ * $1 \leq Y \lt X \leq 100$ * All values in input are integers. ## Input Input is given from Standard Input in the following format: $N$ $A$ $X$ $Y$ [samples]

Samples

Input #1

5 3 20 15

Output #1

90

You need to pay $20$ yen for each of the $1$\-st through $3$\-rd heads of cabbage, and $15$ yen for each of the $4$\-th and $5$\-th heads of cabbage.  
Thus, you need to pay a total of $20+20+20+15+15 = 90$ yen for the $5$ heads of cabbage.

Input #2

10 10 100 1

Output #2

API Response (JSON)

{
  "problem": {
    "name": "Cabbages",
    "description": {
      "content": "Takahashi is visiting a shop specializing in cabbage. The shop sells cabbage for $X$ yen (Japanese currency) per head.   However, if you buy more than $A$ heads of cabbage at once, the $(A+1)$\\-th and",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc210_a"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Takahashi is visiting a shop specializing in cabbage.\nThe shop sells cabbage for $X$ yen (Japanese currency) per head.  \nHowever, if you buy more than $A$ heads of cabbage at once, the $(A+1)$\\-th and...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments