Problem:
Score : 300 points

Problem Statement

Compute A \times B, truncate its fractional part, and print the result as an integer.

Constraints

0 \leq A \leq 10^{15}

0 \leq B < 10

A is an integer.

B is a number with two digits after the decimal point.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the answer as an integer.

Sample Input 1

198 1.10

Sample Output 1

217

We have 198 \times 1.10 = 217.8. After truncating the fractional part, we have the answer: 217.

Sample Input 2

1 0.01

Sample Output 2

0

Sample Input 3

1000000000000000 9.99

Sample Output 3

9990000000000000

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define ll long long 
#define ret return
#define PB push_back
#define lc 2 * v
#define rc 2 * v + 1
#define mid (s + e) / 2
#define pii pair <int,  int>
#define pll pair <long long , long long>  
#define FAST ios::sync_with_stdio(false);cin.tie(0);
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2")
 
const int maxn = 2e5 + 10;
 
int main() {
    FAST
    ll a;
    long double b;
    cin >> a >> b;
    ll val = a * b;
    cout << val << endl;
}