## Problem Solution codechef

*Trick or treat, bags of sweets, ghosts are walking down the street*

It’s Halloween and Suri Bhai is out to get his treats.

There are two sectors in his neighborhood, “Bones” and “Blood”. They have $N$ and $M$ people, respectively.

Each person in “Bones” will hand out $X$ treats, and each person in “Blood” will hand out $Y$ treats.

How many treats does Suri Bhai get from visiting everyone in his neighborhood in total?

### Input Format

- The first line of input contains two space-separated integers $N$ and $M$ — the number of people in “Bones” and “Blood”, respectively.
- The second line of input contains two space-separated integers $X$ and $Y$ — the number of treats handed out by each person in “Bones” and “Blood”, respectively.

### Output Format

For each test case output a single integer: the total number of treats Suri Bhai will receive.

### Constraints

- $0≤N,M≤100$
- $0≤X,Y≤1000$

### Sample 1: [solution] Trick or treat, bags of sweets, ghosts are walking down the street solution codechef

Input

Output

4 2 5 6

32

### Explanation:

- “Bones” has $4$ people, each of who will give out $5$ treats, for a total of $4×5=20$ treats.
- “Blood” has $2$ people, each of who will give out $6$ treats, for a total of $2×6=12$ treats.
- The total number of treats is $20+12=32$.

### Sample 2: [solution] Trick or treat, bags of sweets, ghosts are walking down the street solution codechef

Input

Output

5 0 0 2

0

### Explanation:

- “Bones” has $5$ people, each of who will give out $0$ treats, for a total of $5×0=0$ treats.
- “Blood” has $0$ people, each of who will give out $2$ treats, for a total of $0×2=0$ treats.
- The total number of treats is $0+0=0$.