import java.math.BigDecimal;
import java.util.Scanner;
public class Main{
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String str = sc.nextLine();
String[] arr = str.split(" ");
BigDecimal sum1 = BigDecimal.ONE;
BigDecimal sum2 = BigDecimal.ONE;
BigDecimal sum = BigDecimal.ZERO;
sum1 = sum1.multiply(new BigDecimal(arr[0])).multiply(new BigDecimal(arr[3]));
sum2 = sum2.multiply(new BigDecimal(arr[1])).multiply(new BigDecimal(arr[2]));
sum = sum1.add(sum2);
System.out.print(sum);
}
}
0.0分
1 人评分