// One-star problem
// Problem 10071 Back to High School Physics
/*
This program is written by
Prof. Chua-Huang Huang
Department of Information Engineering and Computer Science
Feng Chia University
Taichung, Taiwan
Disclaimer:
The programming problem is downloaded from UVa Online Judge (https://uva.onlinejudge.org/).
The program solution is provided for helping students to prepare Collegiate Programming
Examination (CPE). The author does not guarantee the program is completely correct to pass
UVa Online Judge platform or CPE examination platform.
This program is not intended for a student to copy only. He/She should practice the
programming problem himself/herself. Only use the program solution as a reference.
The author is not responsible if the program causes any damage of your computer or
personal properties.
No commercial use of this program is allowed without the author's written permission.
*/
#include
#include
// Notation, a: acceleration, t: time, v(t): velocity at time t, d(t): displacement at time t.
// Assume the initial velocity v(0) is 0.
// We have v(t) = a * t and d(t) = (1/2) * a * (t**2).
// Hence, a = v(t) / t and d(2t) = 2 * v(t) * t.
int main(void) {
int v, t; // Variable v is v(t) the velocity at time t.
while (scanf("%d %d", &v, &t)==2) { // Input velocity v(t) and time t until the end of file.
printf("%d\n", 2 * v * t); // Output displacement d(2t) at time 2t.
}
return 0;
}