#include <stdio.h>
#include <string.h>
#include <stdlib.h>
char s[]="abcdefghijklmnopqrstuvwxyz";
char s2[]="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
int main(void)
{
double v;
int t;
int z;
scanf("%lf%d",&v,&t);
z=(double)v*t+0.5;
printf("%d\n",z);


	return 0;
}