#include "bits/stdc++.h"
using namespace std;
#define ff first
#define ss second
#define pb push_back
typedef long long ll;
#define db(x) cerr<<__LINE__<<": "<<#x<<" = "<<(x)<<'\n'
const int inf = 1e9+7;
const int N = 1e6+9;

void solve() {
	long double a, b, n;
	cin>>a>>b;
	ll s=a*b;
	cout<<s<<endl;
}
int main() {
    ios_base::sync_with_stdio(0);
    int T=1 ,cas=0;
    while(T--) {
    	solve();
    }
    return 0;
}

// ll, reset, 1, bottom