Java 代码

/**4 MDKJ
BC is the beginning of something great: a currency without a government, something necessary and imperative. - Nassim Taleb
*/

import java.util.Scanner;

public class Main
{
    public static void main(String[] args)
    {
        Scanner cin = new Scanner(System.in);

        int a = cin.nextInt();
        int b = cin.nextInt();
        int c = cin.nextInt();
        int d = cin.nextInt();

        System.out.println ("DIFERENCA = " + (a * b - c * d));
    }
}