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

#define rep(i,k,n) for(int (i)=(k);(i)<(n);(i)++)
#define max(a,b) (a)>(b)?(a):(b)
#define min(a,b) (a)<(b)?(a):(b)
#define abs(a) (a)>0 ?(a):-(a)
#define llong long long

int main(){
	llong A; scanf("%lld",&A);
	char s[5]; scanf("%s",s);
	llong ans=0;
	ans += (s[0]-'0')*A*100;
	ans += (s[2]-'0')*A*10;
	ans += (s[3]-'0')*A;
	ans /= 100;
	printf("%lld",ans);
	return 0;
}
