#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[]) {
    double v,t;
    scanf("%lf %lf",&v,&t);
    long ans=(long)10*v*t;
    if(ans%10>=5)ans=(ans/10+1);
    else ans=ans/10;
    
    printf("%ld\n",ans);
}