100440: [AtCoder]ABC044 A - Tak and Hotels (ABC Edit)
Memory Limit:256 MB
Time Limit:2 S
Judge Style:Text Compare
Creator:
Submit:4
Solved:0
Description
Score : $100$ points
Problem Statement
There is a hotel with the following accommodation fee:
- $X$ yen (the currency of Japan) per night, for the first $K$ nights
- $Y$ yen per night, for the $(K+1)$-th and subsequent nights
Tak is staying at this hotel for $N$ consecutive nights. Find his total accommodation fee.
Constraints
- $1 \leq N, K \leq 10000$
- $1 \leq Y < X \leq 10000$
- $N,\,K,\,X,\,Y$ are integers.
Input
The input is given from Standard Input in the following format:
$N$ $K$ $X$ $Y$
Output
Print Tak's total accommodation fee.
Sample Input 1
5 3 10000 9000
Sample Output 1
48000
The accommodation fee is as follows:
- $10000$ yen for the $1$-st night
- $10000$ yen for the $2$-nd night
- $10000$ yen for the $3$-rd night
- $9000$ yen for the $4$-th night
- $9000$ yen for the $5$-th night
Thus, the total is $48000$ yen.
Sample Input 2
2 3 10000 9000
Sample Output 2
20000