#include <stdio.h>
#include <math.h>
#include <stdlib.h>

typedef unsigned long long ull;

int	main(void)
{
  	ull	a;
  	char    b[5];
  	char    c[4];
  	ull bb;
  	ull r;

  	scanf("%llu %s", &a, b);
  
    c[0] = b[0];
    c[1] = b[2];
    c[2] = b[3];
    c[3] = '\0';
    bb = (ull)atoi(c);
/*  	bb = (ull)(b * 100.0);
*/  	
    if (a % 100ULL == 0ULL)
    {
        r = a / 100ULL * bb;
    }
    else if (a % 10ULL == 0ULL)
    {
        r = a / 10ULL * bb / 10ULL;
    }
    else
    {
      	r = a * bb / 100ULL;
    }
 
  	printf("%llu", r);
  	return (0);
}