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

int main()
{
  long long int h1;
  double h2;
  scanf("%lld%lf", &h1, &h2);
  long long int big = h1/1000000000000000;
  long long int small = h1%1000000000000000;
  long long int bre, sre;
  // printf("%lld %lf %lld %lld\n", h1, h2, big, small);
  h2 = h2 * 100;
  // printf("%lld %lf %lld %lld\n", h1, h2, big, small);
  long long int h3 = h2;
  // printf("%lld %lf %lld %lld %lld\n", h1, h2, h3, big, small);
  sre = small * h3;
  bre = big * h3 + sre/1000000000000000;
  // printf("%lld %lf %lld %lld %lld\n", h1, h2, h3, bre, sre);  
  sre = sre/100;
  // printf("%lld %lf %lld\n", h1, h2,h3);
  // printf("%lld %lf %lld %lld %lld\n", h1, h2, h3, bre, sre);  
  if(bre > 0){
    if(sre < 10){
      printf("%lld000000000000%lld\n", bre, sre);
    }else if(sre < 100){
      printf("%lld00000000000%lld\n", bre, sre);
    }else if(sre < 1000){
      printf("%lld0000000000%lld\n", bre, sre);
    }else if(sre < 10000){
      printf("%lld000000000%lld\n", bre, sre);
    }else if(sre < 100000){
      printf("%lld00000000%lld\n", bre, sre);
    }else if(sre < 1000000){
      printf("%lld0000000%lld\n", bre, sre);
    }else if(sre < 10000000){
      printf("%lld000000%lld\n", bre, sre);
    }else if(sre < 100000000){
      printf("%lld00000%lld\n", bre, sre);
    }else if(sre < 1000000000){
      printf("%lld0000%lld\n", bre, sre);
    }else if(sre < 10000000000){
      printf("%lld000%lld\n", bre, sre);
    }else if(sre < 100000000000){
      printf("%lld00%lld\n", bre, sre);
    }else if(sre < 1000000000000){
      printf("%lld0%lld\n", bre, sre);
    }else if(sre < 10000000000000){
      printf("%lld%lld\n", bre, sre);
    }
  }else{
    printf("%lld\n", sre);
  }
  
  return 0;
}
