#include<bits/stdc++.h>
using namespace std;

#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define debug(a) cerr << #a << ": " << a << endl
#define int long long
#define endl '\n'

const int N = 2005;


int32_t main()
{
      IOS;

      long double a, b;
      cin>>a>>b;
      int ans = round( a * b);
      cout<<ans;

      return 0;
}
