text: // Program	: CPE - p10071 Back to High School Physics
  // Author	: Timothy William
  // Compiled	: 03/19/2021
  
  #include <stdio.h>
  #include <stdlib.h>
  
  int main(void){
  	int v, t, x;
  
  	// EOF terminates with Ctrl-D
  	while(scanf("%d %d", &v, &t) != EOF){
  		x = v * t * 2;
  		printf("%d\n", x);
  	}
  }
  