#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <map>
#include <set>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <stack>
#include <queue>
#include <utility>
#define rep(i,l,n) for(int i=l;i<n;i++)
#define rer(i,l,n) for(int i=l;i<=n;i++)
#define rrep(i,n,l) for(int i=n-1;i>=l;i--)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
#define pb(a) push_back(a);
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef vector<int> vi;
typedef vector<lint> vli;
typedef vector<vi> vvi;
typedef pair<int,int> pii;

int main(){
	char c;
	string s;
	lint t,l;
	cin>>c>>c>>s>>t;
	//printf("%.4lf\n",v);
	//double vv=v*10000;
	lint v=stoi(s);
	l=v*t;
	lint ans=l/10000;
	o(ans);
}