UVA10071

Problem B

Back to High School Physics

Input: standard input

Output: standard output

A particle has initial velocity and constant acceleration. If its velocity after certain time is v then what will its displacement be in twice of that time?

Input

The input will contain two integers in each line. Each line makes one set of input. These two integers denote the value of v (-100 <= v <= 100) and t(0<=t<= 200) ( t means at the time the particle gains that velocity) 

Output

For each line of input print a single integer in one line denoting the displacement in double of that time.

Sample Input

0 0
5 12

Sample Output

0
120



解法:物理公式

加速度:a 時間:t 初速度:v0

令 v = v0 + a*t


距離為: v0*t+(a*t^2)/2 = 2t*(v0+a*t) = 2*v*t




import java.util.Scanner;

public class UVA10071 {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

while (sc.hasNext()) {
System.out.println(2 * sc.nextInt() * sc.nextInt());
}

sc.close();
}


}