#include<iostream>
#include<cmath>

using namespace std;

int main() {

	int t;
	double v;

	cin >> v >> t;

	v = round(v * 10000);//有効桁まで丸める

	int d = v*t;

	d /= 10000;//戻す

	cout << d << endl;

	return 0;
}