Contest Duration: - (local time) (100 minutes) Back to Home
A - Determinant /

Time Limit: 2 sec / Memory Limit: 1024 MB

### 問題文

2 \times 2 行列 A = \begin{bmatrix} a & b \\ c & d \end{bmatrix} が与えられます。
A の行列式を求めてください。

### 制約

• 入力は全て整数
• -100 \le a, b, c, d \le 100

### 入力

a b
c d


### 入力例 1

1 2
3 4


### 出力例 1

-2


\begin{bmatrix} 1 & 2 \\ 3 & 4 \end{bmatrix} の行列式は 1 \times 4 - 2 \times 3 = -2 です。

### 入力例 2

0 -1
1 0


### 出力例 2

1


### 入力例 3

100 100
100 100


### 出力例 3

0


Score : 100 points

### Problem Statement

Given is a 2 \times 2 matrix A = \begin{bmatrix} a & b \\ c & d \end{bmatrix}.
The determinant of A can be found as ad-bc.
Find it.

### Constraints

• All values in input are integers.
• -100 \le a, b, c, d \le 100

### Input

Input is given from Standard Input in the following format:

a b
c d


### Output

Print the answer as an integer.

### Sample Input 1

1 2
3 4


### Sample Output 1

-2


The determinant of \begin{bmatrix} 1 & 2 \\ 3 & 4 \end{bmatrix} is 1 \times 4 - 2 \times 3 = -2.

### Sample Input 2

0 -1
1 0


### Sample Output 2

1


### Sample Input 3

100 100
100 100


### Sample Output 3

0