#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <iomanip>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include<map>
#include <list>
#include <typeinfo>
using namespace std;
#define REP(a,b) for(long long a = 0;a < b;++a)
int main() {
	int t=0;
	string u;
	cin >> u >> t;
	int hoge = ((int)u[0] - 48) * 10000 + ((int)u[2] - 48) * 1000 + ((int)u[3] - 48) * 100 + ((int)u[4] - 48) * 10 + ((int)u[5] - 48) * 1;
	hoge = hoge*t;
	double ans = hoge / 10000;
	cout << ans << endl;
}
//thank you for reading my code!