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 Hello ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define ll long long
#define endl '\n'
void trace(int n, int arr[]){for(int i = 0; i < n; i++){cout << arr[i] << " ";} cout << endl << endl;}
int main()
{
    Hello
    ll a, b, c;
    char dot;
    cin >> a >> b >> dot >> c;
    b *= 100;
    b += c;
    cout << (a * b)/100;
    return 0;
}