#include <stdio.h>

int main(void){
    long long int a,ansa;
    double b;
    double c;
    //c=(double)100*b;
   
    scanf("%lld %lf",&a,&b);
    c=(double)100.00*b;
    //printf("%lf",c);
    ansa=a*b*1.00+0.001;
    
    printf("%lld\n",ansa);
    return 0;
}