UVA_10071 - Back to High School Physics

/*
Tanzila Islam
CSE, Southeast University.
Dhaka-Bangladesh.
id : https://www.facebook.com/prieontypurnotamohita
mail: tanzilamohita@gmail.com
blog: http://tanzilamohita.blogspot.com/

*/



#include<cstdio>

#include<iostream>

using namespace std;

int main()

{

    int v,t;

    while(scanf("%d %d",&v,&t)==2)

    {

        if(v==0 && t==0)

        cout << "0" << endl;

        else

        cout << 2*v*t << endl;

    }

    return 0;

}