#include<stdio.h>
#include<math.h>
#include<string.h>
#include<>
 
int main(){
  float A,B;
  char t[100000000]
    int i=0;
  while(scanf("%f %f",&A,&B)==0);
  float C=A*B;
  
    sprintf(t,"%f",C);

  while(t[i]!='\0'){
    if(t[i]=='.'){
      break;
    }
    i++;
  }
  
  
  
  printf("%g\n",floor(C));
  
  
  return 0;
}