SOLUTION OF UVA 10071

//   Question of  10071 - Back to High School Physics
//   Mahmud_Jamil






#include<stdio.h>
int main()
{
int s,v,t;
while (scanf("%d%d",&v,&t)!=EOF)
{
s=2*v*t;
printf("%d\n",s);
}
return 0;
}